diff --git a/system/API/ResponseTrait.php b/system/API/ResponseTrait.php
index 5a350007f3..b92a1b808a 100644
--- a/system/API/ResponseTrait.php
+++ b/system/API/ResponseTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Autoloader/Autoloader.php b/system/Autoloader/Autoloader.php
index 020dd5b1a4..4c6fed350f 100644
--- a/system/Autoloader/Autoloader.php
+++ b/system/Autoloader/Autoloader.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Autoloader/FileLocator.php b/system/Autoloader/FileLocator.php
index e3821c1df2..a661f5c49c 100644
--- a/system/Autoloader/FileLocator.php
+++ b/system/Autoloader/FileLocator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Autoloader/FileLocatorCached.php b/system/Autoloader/FileLocatorCached.php
index 8bc8d1e85e..d0748180fa 100644
--- a/system/Autoloader/FileLocatorCached.php
+++ b/system/Autoloader/FileLocatorCached.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Autoloader/FileLocatorInterface.php b/system/Autoloader/FileLocatorInterface.php
index 8f7b551bb0..4d6fc828d8 100644
--- a/system/Autoloader/FileLocatorInterface.php
+++ b/system/Autoloader/FileLocatorInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/BaseModel.php b/system/BaseModel.php
index 7afdf9c1cb..05ed31634f 100644
--- a/system/BaseModel.php
+++ b/system/BaseModel.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/CLI/BaseCommand.php b/system/CLI/BaseCommand.php
index d837f50dbe..eb73435611 100644
--- a/system/CLI/BaseCommand.php
+++ b/system/CLI/BaseCommand.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/CLI/CLI.php b/system/CLI/CLI.php
index e2aa363e58..09a2b6e354 100644
--- a/system/CLI/CLI.php
+++ b/system/CLI/CLI.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/CLI/Commands.php b/system/CLI/Commands.php
index 7cb5351cf3..7dbdecbc50 100644
--- a/system/CLI/Commands.php
+++ b/system/CLI/Commands.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/CLI/Console.php b/system/CLI/Console.php
index adcf9aaeca..90327b9bec 100644
--- a/system/CLI/Console.php
+++ b/system/CLI/Console.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/CLI/Exceptions/CLIException.php b/system/CLI/Exceptions/CLIException.php
index 4e07cd64f9..fae92c001d 100644
--- a/system/CLI/Exceptions/CLIException.php
+++ b/system/CLI/Exceptions/CLIException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/CLI/GeneratorTrait.php b/system/CLI/GeneratorTrait.php
index c1112ca634..349cccb2da 100644
--- a/system/CLI/GeneratorTrait.php
+++ b/system/CLI/GeneratorTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/CacheFactory.php b/system/Cache/CacheFactory.php
index 95e07ef813..66aa82f489 100644
--- a/system/Cache/CacheFactory.php
+++ b/system/Cache/CacheFactory.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/CacheInterface.php b/system/Cache/CacheInterface.php
index 23ea709df4..d76d5aa15b 100644
--- a/system/Cache/CacheInterface.php
+++ b/system/Cache/CacheInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/Exceptions/CacheException.php b/system/Cache/Exceptions/CacheException.php
index 3445590cf9..852e6302ce 100644
--- a/system/Cache/Exceptions/CacheException.php
+++ b/system/Cache/Exceptions/CacheException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/Exceptions/ExceptionInterface.php b/system/Cache/Exceptions/ExceptionInterface.php
index 067e8aa208..31316f0e64 100644
--- a/system/Cache/Exceptions/ExceptionInterface.php
+++ b/system/Cache/Exceptions/ExceptionInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/FactoriesCache.php b/system/Cache/FactoriesCache.php
index d78d0b1b02..e4b7488f43 100644
--- a/system/Cache/FactoriesCache.php
+++ b/system/Cache/FactoriesCache.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/FactoriesCache/FileVarExportHandler.php b/system/Cache/FactoriesCache/FileVarExportHandler.php
index f7cee5ef62..b7c1a043c8 100644
--- a/system/Cache/FactoriesCache/FileVarExportHandler.php
+++ b/system/Cache/FactoriesCache/FileVarExportHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/Handlers/BaseHandler.php b/system/Cache/Handlers/BaseHandler.php
index 061a4a661b..43d316f87b 100644
--- a/system/Cache/Handlers/BaseHandler.php
+++ b/system/Cache/Handlers/BaseHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/Handlers/DummyHandler.php b/system/Cache/Handlers/DummyHandler.php
index d2d4fb068b..10300c7969 100644
--- a/system/Cache/Handlers/DummyHandler.php
+++ b/system/Cache/Handlers/DummyHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/Handlers/FileHandler.php b/system/Cache/Handlers/FileHandler.php
index 0a39c3610b..cf45a6544e 100644
--- a/system/Cache/Handlers/FileHandler.php
+++ b/system/Cache/Handlers/FileHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/Handlers/MemcachedHandler.php b/system/Cache/Handlers/MemcachedHandler.php
index e865890639..e104800407 100644
--- a/system/Cache/Handlers/MemcachedHandler.php
+++ b/system/Cache/Handlers/MemcachedHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/Handlers/PredisHandler.php b/system/Cache/Handlers/PredisHandler.php
index 986d083ebc..d08205222a 100644
--- a/system/Cache/Handlers/PredisHandler.php
+++ b/system/Cache/Handlers/PredisHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/Handlers/RedisHandler.php b/system/Cache/Handlers/RedisHandler.php
index 953de2dc20..e80119de89 100644
--- a/system/Cache/Handlers/RedisHandler.php
+++ b/system/Cache/Handlers/RedisHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/Handlers/WincacheHandler.php b/system/Cache/Handlers/WincacheHandler.php
index b1ea45ded7..0ddee50a7f 100644
--- a/system/Cache/Handlers/WincacheHandler.php
+++ b/system/Cache/Handlers/WincacheHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cache/ResponseCache.php b/system/Cache/ResponseCache.php
index 6e8e8b4887..d0f15fdff1 100644
--- a/system/Cache/ResponseCache.php
+++ b/system/Cache/ResponseCache.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/CodeIgniter.php b/system/CodeIgniter.php
index 87a2a55b0c..368b6130cf 100644
--- a/system/CodeIgniter.php
+++ b/system/CodeIgniter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Cache/ClearCache.php b/system/Commands/Cache/ClearCache.php
index 79fab9dfae..e1180c28c6 100644
--- a/system/Commands/Cache/ClearCache.php
+++ b/system/Commands/Cache/ClearCache.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Cache/InfoCache.php b/system/Commands/Cache/InfoCache.php
index 1dc2504b0f..abeabd7fed 100644
--- a/system/Commands/Cache/InfoCache.php
+++ b/system/Commands/Cache/InfoCache.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Database/CreateDatabase.php b/system/Commands/Database/CreateDatabase.php
index d103d97f68..4122e315ff 100644
--- a/system/Commands/Database/CreateDatabase.php
+++ b/system/Commands/Database/CreateDatabase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Database/Migrate.php b/system/Commands/Database/Migrate.php
index 119335170d..50b3c8f9e0 100644
--- a/system/Commands/Database/Migrate.php
+++ b/system/Commands/Database/Migrate.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Database/MigrateRefresh.php b/system/Commands/Database/MigrateRefresh.php
index f683219e9d..e5e8a6d967 100644
--- a/system/Commands/Database/MigrateRefresh.php
+++ b/system/Commands/Database/MigrateRefresh.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Database/MigrateRollback.php b/system/Commands/Database/MigrateRollback.php
index 2df223c0f8..200dc303db 100644
--- a/system/Commands/Database/MigrateRollback.php
+++ b/system/Commands/Database/MigrateRollback.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Database/MigrateStatus.php b/system/Commands/Database/MigrateStatus.php
index 0ef0780802..5105eaa1da 100644
--- a/system/Commands/Database/MigrateStatus.php
+++ b/system/Commands/Database/MigrateStatus.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Database/Seed.php b/system/Commands/Database/Seed.php
index adfdd0a5f7..fc1c0f1ae6 100644
--- a/system/Commands/Database/Seed.php
+++ b/system/Commands/Database/Seed.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Database/ShowTableInfo.php b/system/Commands/Database/ShowTableInfo.php
index 736c7ab994..9221f6e5c4 100644
--- a/system/Commands/Database/ShowTableInfo.php
+++ b/system/Commands/Database/ShowTableInfo.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Encryption/GenerateKey.php b/system/Commands/Encryption/GenerateKey.php
index 419ae6ef3e..4409560b04 100644
--- a/system/Commands/Encryption/GenerateKey.php
+++ b/system/Commands/Encryption/GenerateKey.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/CellGenerator.php b/system/Commands/Generators/CellGenerator.php
index 3d31231697..57d79ac890 100644
--- a/system/Commands/Generators/CellGenerator.php
+++ b/system/Commands/Generators/CellGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/CommandGenerator.php b/system/Commands/Generators/CommandGenerator.php
index 3a47e68ac7..8c2ebcfb5d 100644
--- a/system/Commands/Generators/CommandGenerator.php
+++ b/system/Commands/Generators/CommandGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/ConfigGenerator.php b/system/Commands/Generators/ConfigGenerator.php
index 217c00be46..7b1d5f21ff 100644
--- a/system/Commands/Generators/ConfigGenerator.php
+++ b/system/Commands/Generators/ConfigGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/ControllerGenerator.php b/system/Commands/Generators/ControllerGenerator.php
index 869bd5d15e..c6f54cac28 100644
--- a/system/Commands/Generators/ControllerGenerator.php
+++ b/system/Commands/Generators/ControllerGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/EntityGenerator.php b/system/Commands/Generators/EntityGenerator.php
index 4cb44ad32d..09c3505606 100644
--- a/system/Commands/Generators/EntityGenerator.php
+++ b/system/Commands/Generators/EntityGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/FilterGenerator.php b/system/Commands/Generators/FilterGenerator.php
index ad1fa2da69..c723da3afa 100644
--- a/system/Commands/Generators/FilterGenerator.php
+++ b/system/Commands/Generators/FilterGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/MigrationGenerator.php b/system/Commands/Generators/MigrationGenerator.php
index de648d130c..b7d7d585e9 100644
--- a/system/Commands/Generators/MigrationGenerator.php
+++ b/system/Commands/Generators/MigrationGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/ModelGenerator.php b/system/Commands/Generators/ModelGenerator.php
index 6a817ef50e..5450bda79b 100644
--- a/system/Commands/Generators/ModelGenerator.php
+++ b/system/Commands/Generators/ModelGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/ScaffoldGenerator.php b/system/Commands/Generators/ScaffoldGenerator.php
index ef34b92ed5..3b1ef7957c 100644
--- a/system/Commands/Generators/ScaffoldGenerator.php
+++ b/system/Commands/Generators/ScaffoldGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/SeederGenerator.php b/system/Commands/Generators/SeederGenerator.php
index b4a6d76ad4..0549ad840a 100644
--- a/system/Commands/Generators/SeederGenerator.php
+++ b/system/Commands/Generators/SeederGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Generators/ValidationGenerator.php b/system/Commands/Generators/ValidationGenerator.php
index 0a116f0716..d9e3d495a7 100644
--- a/system/Commands/Generators/ValidationGenerator.php
+++ b/system/Commands/Generators/ValidationGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Help.php b/system/Commands/Help.php
index 338a5c868c..76913e8a33 100644
--- a/system/Commands/Help.php
+++ b/system/Commands/Help.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Housekeeping/ClearDebugbar.php b/system/Commands/Housekeeping/ClearDebugbar.php
index da6f76a47b..2a5c9fa4b5 100644
--- a/system/Commands/Housekeeping/ClearDebugbar.php
+++ b/system/Commands/Housekeeping/ClearDebugbar.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Housekeeping/ClearLogs.php b/system/Commands/Housekeeping/ClearLogs.php
index 56cfeab36a..ec4b700e07 100644
--- a/system/Commands/Housekeeping/ClearLogs.php
+++ b/system/Commands/Housekeeping/ClearLogs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/ListCommands.php b/system/Commands/ListCommands.php
index 9accecf0ad..778f8f955b 100644
--- a/system/Commands/ListCommands.php
+++ b/system/Commands/ListCommands.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Server/Serve.php b/system/Commands/Server/Serve.php
index b53820205f..c32cd6560a 100644
--- a/system/Commands/Server/Serve.php
+++ b/system/Commands/Server/Serve.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Server/rewrite.php b/system/Commands/Server/rewrite.php
index 45a10936b1..f936cd63f0 100644
--- a/system/Commands/Server/rewrite.php
+++ b/system/Commands/Server/rewrite.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Translation/LocalizationFinder.php b/system/Commands/Translation/LocalizationFinder.php
index d8fbbf1aad..df0c41d04c 100644
--- a/system/Commands/Translation/LocalizationFinder.php
+++ b/system/Commands/Translation/LocalizationFinder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Environment.php b/system/Commands/Utilities/Environment.php
index fd8f68fabd..17a08d21d2 100644
--- a/system/Commands/Utilities/Environment.php
+++ b/system/Commands/Utilities/Environment.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/FilterCheck.php b/system/Commands/Utilities/FilterCheck.php
index 57b5731333..a3b750b0b4 100644
--- a/system/Commands/Utilities/FilterCheck.php
+++ b/system/Commands/Utilities/FilterCheck.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Namespaces.php b/system/Commands/Utilities/Namespaces.php
index 71461933c5..47450812b4 100644
--- a/system/Commands/Utilities/Namespaces.php
+++ b/system/Commands/Utilities/Namespaces.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Publish.php b/system/Commands/Utilities/Publish.php
index 1e4103c114..35a9163404 100644
--- a/system/Commands/Utilities/Publish.php
+++ b/system/Commands/Utilities/Publish.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Routes.php b/system/Commands/Utilities/Routes.php
index 79a4e741bb..812d9a8ac4 100644
--- a/system/Commands/Utilities/Routes.php
+++ b/system/Commands/Utilities/Routes.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Routes/AutoRouteCollector.php b/system/Commands/Utilities/Routes/AutoRouteCollector.php
index cc45608f21..6a3f1ae12b 100644
--- a/system/Commands/Utilities/Routes/AutoRouteCollector.php
+++ b/system/Commands/Utilities/Routes/AutoRouteCollector.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Routes/AutoRouterImproved/AutoRouteCollector.php b/system/Commands/Utilities/Routes/AutoRouterImproved/AutoRouteCollector.php
index 18a158cffa..a1548da81f 100644
--- a/system/Commands/Utilities/Routes/AutoRouterImproved/AutoRouteCollector.php
+++ b/system/Commands/Utilities/Routes/AutoRouterImproved/AutoRouteCollector.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Routes/AutoRouterImproved/ControllerMethodReader.php b/system/Commands/Utilities/Routes/AutoRouterImproved/ControllerMethodReader.php
index 73da88630d..cd255baa76 100644
--- a/system/Commands/Utilities/Routes/AutoRouterImproved/ControllerMethodReader.php
+++ b/system/Commands/Utilities/Routes/AutoRouterImproved/ControllerMethodReader.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Routes/ControllerFinder.php b/system/Commands/Utilities/Routes/ControllerFinder.php
index 4611051462..2121beab5e 100644
--- a/system/Commands/Utilities/Routes/ControllerFinder.php
+++ b/system/Commands/Utilities/Routes/ControllerFinder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Routes/ControllerMethodReader.php b/system/Commands/Utilities/Routes/ControllerMethodReader.php
index 31bcde12df..be28ef4e2e 100644
--- a/system/Commands/Utilities/Routes/ControllerMethodReader.php
+++ b/system/Commands/Utilities/Routes/ControllerMethodReader.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Routes/FilterCollector.php b/system/Commands/Utilities/Routes/FilterCollector.php
index 0135a6a535..7db6d64848 100644
--- a/system/Commands/Utilities/Routes/FilterCollector.php
+++ b/system/Commands/Utilities/Routes/FilterCollector.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Routes/FilterFinder.php b/system/Commands/Utilities/Routes/FilterFinder.php
index cc1f6d2b05..5e0b0cf1c2 100644
--- a/system/Commands/Utilities/Routes/FilterFinder.php
+++ b/system/Commands/Utilities/Routes/FilterFinder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Commands/Utilities/Routes/SampleURIGenerator.php b/system/Commands/Utilities/Routes/SampleURIGenerator.php
index 43d1934438..5ed0075c77 100644
--- a/system/Commands/Utilities/Routes/SampleURIGenerator.php
+++ b/system/Commands/Utilities/Routes/SampleURIGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Common.php b/system/Common.php
index 0f8aa3e7ad..dbe6ebf1ec 100644
--- a/system/Common.php
+++ b/system/Common.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/ComposerScripts.php b/system/ComposerScripts.php
index 021079da46..3e3ec7bd1d 100644
--- a/system/ComposerScripts.php
+++ b/system/ComposerScripts.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/AutoloadConfig.php b/system/Config/AutoloadConfig.php
index eb210f626d..d5f515ecdf 100644
--- a/system/Config/AutoloadConfig.php
+++ b/system/Config/AutoloadConfig.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/BaseConfig.php b/system/Config/BaseConfig.php
index 216ce81fd5..ed6fa3e2bc 100644
--- a/system/Config/BaseConfig.php
+++ b/system/Config/BaseConfig.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/BaseService.php b/system/Config/BaseService.php
index 970977dd41..571b65d68c 100644
--- a/system/Config/BaseService.php
+++ b/system/Config/BaseService.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/DotEnv.php b/system/Config/DotEnv.php
index 05ecab900c..640afd4ce8 100644
--- a/system/Config/DotEnv.php
+++ b/system/Config/DotEnv.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/Factories.php b/system/Config/Factories.php
index 253cd3f7a7..c4f443cc3a 100644
--- a/system/Config/Factories.php
+++ b/system/Config/Factories.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/Factory.php b/system/Config/Factory.php
index 5889bf4d73..b25267791b 100644
--- a/system/Config/Factory.php
+++ b/system/Config/Factory.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/ForeignCharacters.php b/system/Config/ForeignCharacters.php
index a8569f5419..2663a53a82 100644
--- a/system/Config/ForeignCharacters.php
+++ b/system/Config/ForeignCharacters.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/Publisher.php b/system/Config/Publisher.php
index d5f938e09b..7e1b0ffb54 100644
--- a/system/Config/Publisher.php
+++ b/system/Config/Publisher.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/Routing.php b/system/Config/Routing.php
index e6d25138f8..af4f4147c4 100644
--- a/system/Config/Routing.php
+++ b/system/Config/Routing.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/Services.php b/system/Config/Services.php
index 5ffb9e049c..0ca36751dc 100644
--- a/system/Config/Services.php
+++ b/system/Config/Services.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Config/View.php b/system/Config/View.php
index 101b67f580..8a4adc7982 100644
--- a/system/Config/View.php
+++ b/system/Config/View.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Controller.php b/system/Controller.php
index c040e1d20a..2b7dd3f579 100644
--- a/system/Controller.php
+++ b/system/Controller.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cookie/CloneableCookieInterface.php b/system/Cookie/CloneableCookieInterface.php
index 93f6031e20..0b7d6fdf50 100644
--- a/system/Cookie/CloneableCookieInterface.php
+++ b/system/Cookie/CloneableCookieInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cookie/Cookie.php b/system/Cookie/Cookie.php
index 68a748cb30..7a0532e9ee 100644
--- a/system/Cookie/Cookie.php
+++ b/system/Cookie/Cookie.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cookie/CookieInterface.php b/system/Cookie/CookieInterface.php
index 5a21d6ad83..c848fa8884 100644
--- a/system/Cookie/CookieInterface.php
+++ b/system/Cookie/CookieInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cookie/CookieStore.php b/system/Cookie/CookieStore.php
index d893a4add1..9c183bec4a 100644
--- a/system/Cookie/CookieStore.php
+++ b/system/Cookie/CookieStore.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Cookie/Exceptions/CookieException.php b/system/Cookie/Exceptions/CookieException.php
index 2e69a0e0f8..cc785654ef 100644
--- a/system/Cookie/Exceptions/CookieException.php
+++ b/system/Cookie/Exceptions/CookieException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/BaseBuilder.php b/system/Database/BaseBuilder.php
index badf2d35cd..0e6ea89534 100644
--- a/system/Database/BaseBuilder.php
+++ b/system/Database/BaseBuilder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/BaseConnection.php b/system/Database/BaseConnection.php
index eac85ef56d..76696dd911 100644
--- a/system/Database/BaseConnection.php
+++ b/system/Database/BaseConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/BasePreparedQuery.php b/system/Database/BasePreparedQuery.php
index 22da47f990..3a4967307d 100644
--- a/system/Database/BasePreparedQuery.php
+++ b/system/Database/BasePreparedQuery.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/BaseResult.php b/system/Database/BaseResult.php
index 6f6399cfb2..a98c6e7612 100644
--- a/system/Database/BaseResult.php
+++ b/system/Database/BaseResult.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/BaseUtils.php b/system/Database/BaseUtils.php
index a3d878ad7f..27b369c5cb 100644
--- a/system/Database/BaseUtils.php
+++ b/system/Database/BaseUtils.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Config.php b/system/Database/Config.php
index 92556c6d8f..07357cf3b3 100644
--- a/system/Database/Config.php
+++ b/system/Database/Config.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/ConnectionInterface.php b/system/Database/ConnectionInterface.php
index 85125eb1ae..188d44b361 100644
--- a/system/Database/ConnectionInterface.php
+++ b/system/Database/ConnectionInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Database.php b/system/Database/Database.php
index 2818fe2209..3d51a5dfc0 100644
--- a/system/Database/Database.php
+++ b/system/Database/Database.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Exceptions/DataException.php b/system/Database/Exceptions/DataException.php
index 09b9ff3297..18a54171cc 100644
--- a/system/Database/Exceptions/DataException.php
+++ b/system/Database/Exceptions/DataException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Exceptions/DatabaseException.php b/system/Database/Exceptions/DatabaseException.php
index 4a5878782c..cdb8e22832 100644
--- a/system/Database/Exceptions/DatabaseException.php
+++ b/system/Database/Exceptions/DatabaseException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Exceptions/ExceptionInterface.php b/system/Database/Exceptions/ExceptionInterface.php
index 8156523493..915adffb4e 100644
--- a/system/Database/Exceptions/ExceptionInterface.php
+++ b/system/Database/Exceptions/ExceptionInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Forge.php b/system/Database/Forge.php
index 57e43bf199..7dfea30154 100644
--- a/system/Database/Forge.php
+++ b/system/Database/Forge.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Migration.php b/system/Database/Migration.php
index 1616830f92..982f947988 100644
--- a/system/Database/Migration.php
+++ b/system/Database/Migration.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/MigrationRunner.php b/system/Database/MigrationRunner.php
index 4b342eeaac..6452e1cd42 100644
--- a/system/Database/MigrationRunner.php
+++ b/system/Database/MigrationRunner.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/MySQLi/Builder.php b/system/Database/MySQLi/Builder.php
index 2b95aedcea..092196f0ac 100644
--- a/system/Database/MySQLi/Builder.php
+++ b/system/Database/MySQLi/Builder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/MySQLi/Connection.php b/system/Database/MySQLi/Connection.php
index 45b306ce2a..135b398b35 100644
--- a/system/Database/MySQLi/Connection.php
+++ b/system/Database/MySQLi/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/MySQLi/Forge.php b/system/Database/MySQLi/Forge.php
index 0d294c2d09..cb4c446426 100644
--- a/system/Database/MySQLi/Forge.php
+++ b/system/Database/MySQLi/Forge.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/MySQLi/PreparedQuery.php b/system/Database/MySQLi/PreparedQuery.php
index 594fcba249..e9a6c6d10e 100644
--- a/system/Database/MySQLi/PreparedQuery.php
+++ b/system/Database/MySQLi/PreparedQuery.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/MySQLi/Result.php b/system/Database/MySQLi/Result.php
index 578169deb7..873bbd08b9 100644
--- a/system/Database/MySQLi/Result.php
+++ b/system/Database/MySQLi/Result.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/MySQLi/Utils.php b/system/Database/MySQLi/Utils.php
index 08989f75dd..be68367361 100644
--- a/system/Database/MySQLi/Utils.php
+++ b/system/Database/MySQLi/Utils.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/OCI8/Builder.php b/system/Database/OCI8/Builder.php
index bccb0bc547..d43637250d 100644
--- a/system/Database/OCI8/Builder.php
+++ b/system/Database/OCI8/Builder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/OCI8/Connection.php b/system/Database/OCI8/Connection.php
index 8cb7e3a4a7..90be847f1e 100644
--- a/system/Database/OCI8/Connection.php
+++ b/system/Database/OCI8/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/OCI8/Forge.php b/system/Database/OCI8/Forge.php
index 6e1e85f666..8ae1d28bc9 100644
--- a/system/Database/OCI8/Forge.php
+++ b/system/Database/OCI8/Forge.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/OCI8/PreparedQuery.php b/system/Database/OCI8/PreparedQuery.php
index 93d260707f..c267f80613 100644
--- a/system/Database/OCI8/PreparedQuery.php
+++ b/system/Database/OCI8/PreparedQuery.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/OCI8/Result.php b/system/Database/OCI8/Result.php
index 01025763d4..0039e90ae9 100644
--- a/system/Database/OCI8/Result.php
+++ b/system/Database/OCI8/Result.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/OCI8/Utils.php b/system/Database/OCI8/Utils.php
index 2f3a3304ea..c6e97963fa 100644
--- a/system/Database/OCI8/Utils.php
+++ b/system/Database/OCI8/Utils.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Postgre/Builder.php b/system/Database/Postgre/Builder.php
index d4be734b5b..8b2754a6c2 100644
--- a/system/Database/Postgre/Builder.php
+++ b/system/Database/Postgre/Builder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Postgre/Connection.php b/system/Database/Postgre/Connection.php
index 56905ec922..da96bf8edb 100644
--- a/system/Database/Postgre/Connection.php
+++ b/system/Database/Postgre/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Postgre/Forge.php b/system/Database/Postgre/Forge.php
index 47be1b063c..bb592b2688 100644
--- a/system/Database/Postgre/Forge.php
+++ b/system/Database/Postgre/Forge.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Postgre/PreparedQuery.php b/system/Database/Postgre/PreparedQuery.php
index fd60793dbe..1ba144071b 100644
--- a/system/Database/Postgre/PreparedQuery.php
+++ b/system/Database/Postgre/PreparedQuery.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Postgre/Result.php b/system/Database/Postgre/Result.php
index 0a82875763..e5d78c519c 100644
--- a/system/Database/Postgre/Result.php
+++ b/system/Database/Postgre/Result.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Postgre/Utils.php b/system/Database/Postgre/Utils.php
index 516104ec95..c3b7b82d16 100644
--- a/system/Database/Postgre/Utils.php
+++ b/system/Database/Postgre/Utils.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/PreparedQueryInterface.php b/system/Database/PreparedQueryInterface.php
index 7b55991835..1599887031 100644
--- a/system/Database/PreparedQueryInterface.php
+++ b/system/Database/PreparedQueryInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Query.php b/system/Database/Query.php
index 897a668f13..ebd9c279bd 100644
--- a/system/Database/Query.php
+++ b/system/Database/Query.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/QueryInterface.php b/system/Database/QueryInterface.php
index 4f40f004f7..19cbdd0edc 100644
--- a/system/Database/QueryInterface.php
+++ b/system/Database/QueryInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/RawSql.php b/system/Database/RawSql.php
index efa97d3073..0a2abf0d15 100644
--- a/system/Database/RawSql.php
+++ b/system/Database/RawSql.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/ResultInterface.php b/system/Database/ResultInterface.php
index b06de85ad3..2a1bb1c80b 100644
--- a/system/Database/ResultInterface.php
+++ b/system/Database/ResultInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLSRV/Builder.php b/system/Database/SQLSRV/Builder.php
index 5e3e4a73bb..e7ee8eca83 100755
--- a/system/Database/SQLSRV/Builder.php
+++ b/system/Database/SQLSRV/Builder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLSRV/Connection.php b/system/Database/SQLSRV/Connection.php
index 9e00329b72..ee38323894 100755
--- a/system/Database/SQLSRV/Connection.php
+++ b/system/Database/SQLSRV/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLSRV/Forge.php b/system/Database/SQLSRV/Forge.php
index e446247618..68a47c3bc2 100755
--- a/system/Database/SQLSRV/Forge.php
+++ b/system/Database/SQLSRV/Forge.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLSRV/PreparedQuery.php b/system/Database/SQLSRV/PreparedQuery.php
index f752e76934..f3a4a14c2b 100755
--- a/system/Database/SQLSRV/PreparedQuery.php
+++ b/system/Database/SQLSRV/PreparedQuery.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLSRV/Result.php b/system/Database/SQLSRV/Result.php
index f245a01669..4d9b836fdd 100755
--- a/system/Database/SQLSRV/Result.php
+++ b/system/Database/SQLSRV/Result.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLSRV/Utils.php b/system/Database/SQLSRV/Utils.php
index ae52ae40a7..f74ac39f7a 100755
--- a/system/Database/SQLSRV/Utils.php
+++ b/system/Database/SQLSRV/Utils.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLite3/Builder.php b/system/Database/SQLite3/Builder.php
index 994ac69a5c..a59270bbc0 100644
--- a/system/Database/SQLite3/Builder.php
+++ b/system/Database/SQLite3/Builder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLite3/Connection.php b/system/Database/SQLite3/Connection.php
index f41c8e4de7..b18a36f429 100644
--- a/system/Database/SQLite3/Connection.php
+++ b/system/Database/SQLite3/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLite3/Forge.php b/system/Database/SQLite3/Forge.php
index b1dcb1dd59..d686c1c09c 100644
--- a/system/Database/SQLite3/Forge.php
+++ b/system/Database/SQLite3/Forge.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLite3/PreparedQuery.php b/system/Database/SQLite3/PreparedQuery.php
index e892e73bde..5afa72f030 100644
--- a/system/Database/SQLite3/PreparedQuery.php
+++ b/system/Database/SQLite3/PreparedQuery.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLite3/Result.php b/system/Database/SQLite3/Result.php
index f3887b044b..70d8dc47d2 100644
--- a/system/Database/SQLite3/Result.php
+++ b/system/Database/SQLite3/Result.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLite3/Table.php b/system/Database/SQLite3/Table.php
index 879437da6f..6c24ec43fa 100644
--- a/system/Database/SQLite3/Table.php
+++ b/system/Database/SQLite3/Table.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/SQLite3/Utils.php b/system/Database/SQLite3/Utils.php
index b8f45dd541..93f7f0e00d 100644
--- a/system/Database/SQLite3/Utils.php
+++ b/system/Database/SQLite3/Utils.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Database/Seeder.php b/system/Database/Seeder.php
index 749f6f34d5..ec65de7741 100644
--- a/system/Database/Seeder.php
+++ b/system/Database/Seeder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/BaseExceptionHandler.php b/system/Debug/BaseExceptionHandler.php
index 8b67d2153f..bab7c10512 100644
--- a/system/Debug/BaseExceptionHandler.php
+++ b/system/Debug/BaseExceptionHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/ExceptionHandler.php b/system/Debug/ExceptionHandler.php
index 63449888ff..52a1b7a52c 100644
--- a/system/Debug/ExceptionHandler.php
+++ b/system/Debug/ExceptionHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/ExceptionHandlerInterface.php b/system/Debug/ExceptionHandlerInterface.php
index bbfcb6ba70..d0379e2abd 100644
--- a/system/Debug/ExceptionHandlerInterface.php
+++ b/system/Debug/ExceptionHandlerInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Exceptions.php b/system/Debug/Exceptions.php
index da5ce93737..855abe30aa 100644
--- a/system/Debug/Exceptions.php
+++ b/system/Debug/Exceptions.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Iterator.php b/system/Debug/Iterator.php
index 2163bb0b25..543e16d8c5 100644
--- a/system/Debug/Iterator.php
+++ b/system/Debug/Iterator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Timer.php b/system/Debug/Timer.php
index 103094b0a6..a4b889f457 100644
--- a/system/Debug/Timer.php
+++ b/system/Debug/Timer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar.php b/system/Debug/Toolbar.php
index 3f846a36d2..6940f79c1e 100644
--- a/system/Debug/Toolbar.php
+++ b/system/Debug/Toolbar.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/BaseCollector.php b/system/Debug/Toolbar/Collectors/BaseCollector.php
index 4704fcdcaa..81cc631f98 100644
--- a/system/Debug/Toolbar/Collectors/BaseCollector.php
+++ b/system/Debug/Toolbar/Collectors/BaseCollector.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/Config.php b/system/Debug/Toolbar/Collectors/Config.php
index faf7a19b73..1ed23d1cf5 100644
--- a/system/Debug/Toolbar/Collectors/Config.php
+++ b/system/Debug/Toolbar/Collectors/Config.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/Database.php b/system/Debug/Toolbar/Collectors/Database.php
index b527f2ed3c..d9ea335a11 100644
--- a/system/Debug/Toolbar/Collectors/Database.php
+++ b/system/Debug/Toolbar/Collectors/Database.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/Events.php b/system/Debug/Toolbar/Collectors/Events.php
index 178a886644..173c71a327 100644
--- a/system/Debug/Toolbar/Collectors/Events.php
+++ b/system/Debug/Toolbar/Collectors/Events.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/Files.php b/system/Debug/Toolbar/Collectors/Files.php
index c281906cdd..df226d00f6 100644
--- a/system/Debug/Toolbar/Collectors/Files.php
+++ b/system/Debug/Toolbar/Collectors/Files.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/History.php b/system/Debug/Toolbar/Collectors/History.php
index a639e35a4e..b3e9e61e4e 100644
--- a/system/Debug/Toolbar/Collectors/History.php
+++ b/system/Debug/Toolbar/Collectors/History.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/Logs.php b/system/Debug/Toolbar/Collectors/Logs.php
index d656ca9bce..2194526c73 100644
--- a/system/Debug/Toolbar/Collectors/Logs.php
+++ b/system/Debug/Toolbar/Collectors/Logs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/Routes.php b/system/Debug/Toolbar/Collectors/Routes.php
index 46aa916440..19b883ec19 100644
--- a/system/Debug/Toolbar/Collectors/Routes.php
+++ b/system/Debug/Toolbar/Collectors/Routes.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/Timers.php b/system/Debug/Toolbar/Collectors/Timers.php
index cfce9e6175..163c9f5743 100644
--- a/system/Debug/Toolbar/Collectors/Timers.php
+++ b/system/Debug/Toolbar/Collectors/Timers.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Collectors/Views.php b/system/Debug/Toolbar/Collectors/Views.php
index ea44dae44b..839944e356 100644
--- a/system/Debug/Toolbar/Collectors/Views.php
+++ b/system/Debug/Toolbar/Collectors/Views.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Debug/Toolbar/Views/toolbar.tpl.php b/system/Debug/Toolbar/Views/toolbar.tpl.php
index aadf72ee19..581b8c0d17 100644
--- a/system/Debug/Toolbar/Views/toolbar.tpl.php
+++ b/system/Debug/Toolbar/Views/toolbar.tpl.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 /**
  * @var \CodeIgniter\Debug\Toolbar $this
  * @var int                        $totalTime
diff --git a/system/Email/Email.php b/system/Email/Email.php
index 27e5bc83b6..de33d89214 100644
--- a/system/Email/Email.php
+++ b/system/Email/Email.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Encryption/EncrypterInterface.php b/system/Encryption/EncrypterInterface.php
index 161238177c..2f40995041 100644
--- a/system/Encryption/EncrypterInterface.php
+++ b/system/Encryption/EncrypterInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Encryption/Encryption.php b/system/Encryption/Encryption.php
index 113703d556..93236a581f 100644
--- a/system/Encryption/Encryption.php
+++ b/system/Encryption/Encryption.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Encryption/Exceptions/EncryptionException.php b/system/Encryption/Exceptions/EncryptionException.php
index 41a96b69e3..c2220bb88c 100644
--- a/system/Encryption/Exceptions/EncryptionException.php
+++ b/system/Encryption/Exceptions/EncryptionException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Encryption/Handlers/BaseHandler.php b/system/Encryption/Handlers/BaseHandler.php
index 08c0234a5d..365ed961d3 100644
--- a/system/Encryption/Handlers/BaseHandler.php
+++ b/system/Encryption/Handlers/BaseHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Encryption/Handlers/OpenSSLHandler.php b/system/Encryption/Handlers/OpenSSLHandler.php
index 0d8f10758b..f3b62c64a4 100644
--- a/system/Encryption/Handlers/OpenSSLHandler.php
+++ b/system/Encryption/Handlers/OpenSSLHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Encryption/Handlers/SodiumHandler.php b/system/Encryption/Handlers/SodiumHandler.php
index c483dfe90c..b6c74da765 100644
--- a/system/Encryption/Handlers/SodiumHandler.php
+++ b/system/Encryption/Handlers/SodiumHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity.php b/system/Entity.php
index 94aa7241ff..a27e0d3068 100644
--- a/system/Entity.php
+++ b/system/Entity.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/ArrayCast.php b/system/Entity/Cast/ArrayCast.php
index 315f2e582f..02b67078bd 100644
--- a/system/Entity/Cast/ArrayCast.php
+++ b/system/Entity/Cast/ArrayCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/BaseCast.php b/system/Entity/Cast/BaseCast.php
index bfb156da3e..34cb28e787 100644
--- a/system/Entity/Cast/BaseCast.php
+++ b/system/Entity/Cast/BaseCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/BooleanCast.php b/system/Entity/Cast/BooleanCast.php
index f46f5f5326..8d95ba24b1 100644
--- a/system/Entity/Cast/BooleanCast.php
+++ b/system/Entity/Cast/BooleanCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/CSVCast.php b/system/Entity/Cast/CSVCast.php
index ba24142735..7b8be55d52 100644
--- a/system/Entity/Cast/CSVCast.php
+++ b/system/Entity/Cast/CSVCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/CastInterface.php b/system/Entity/Cast/CastInterface.php
index c1dcf1c40e..1820bb45d8 100644
--- a/system/Entity/Cast/CastInterface.php
+++ b/system/Entity/Cast/CastInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/DatetimeCast.php b/system/Entity/Cast/DatetimeCast.php
index 5bfc533e08..2d01ad79b0 100644
--- a/system/Entity/Cast/DatetimeCast.php
+++ b/system/Entity/Cast/DatetimeCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/FloatCast.php b/system/Entity/Cast/FloatCast.php
index 78f87570f3..642e849e74 100644
--- a/system/Entity/Cast/FloatCast.php
+++ b/system/Entity/Cast/FloatCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/IntBoolCast.php b/system/Entity/Cast/IntBoolCast.php
index ce572d9eba..fb1c470e89 100644
--- a/system/Entity/Cast/IntBoolCast.php
+++ b/system/Entity/Cast/IntBoolCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/IntegerCast.php b/system/Entity/Cast/IntegerCast.php
index b9357d7ed4..c0ecec7324 100644
--- a/system/Entity/Cast/IntegerCast.php
+++ b/system/Entity/Cast/IntegerCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/JsonCast.php b/system/Entity/Cast/JsonCast.php
index 534631be61..ef389269ed 100644
--- a/system/Entity/Cast/JsonCast.php
+++ b/system/Entity/Cast/JsonCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/ObjectCast.php b/system/Entity/Cast/ObjectCast.php
index 0a22ed8a4a..1bee213d50 100644
--- a/system/Entity/Cast/ObjectCast.php
+++ b/system/Entity/Cast/ObjectCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/StringCast.php b/system/Entity/Cast/StringCast.php
index 974567ccb6..e4ed04b94d 100644
--- a/system/Entity/Cast/StringCast.php
+++ b/system/Entity/Cast/StringCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/TimestampCast.php b/system/Entity/Cast/TimestampCast.php
index f9669d592e..a445badec1 100644
--- a/system/Entity/Cast/TimestampCast.php
+++ b/system/Entity/Cast/TimestampCast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Cast/URICast.php b/system/Entity/Cast/URICast.php
index bb49e7454d..d0d510b109 100644
--- a/system/Entity/Cast/URICast.php
+++ b/system/Entity/Cast/URICast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Entity.php b/system/Entity/Entity.php
index 90d3ab46a2..6b285796ae 100644
--- a/system/Entity/Entity.php
+++ b/system/Entity/Entity.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Entity/Exceptions/CastException.php b/system/Entity/Exceptions/CastException.php
index e259447b3f..f0e95576c9 100644
--- a/system/Entity/Exceptions/CastException.php
+++ b/system/Entity/Exceptions/CastException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Events/Events.php b/system/Events/Events.php
index b240dc29e1..6647d6c9b4 100644
--- a/system/Events/Events.php
+++ b/system/Events/Events.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/AlertError.php b/system/Exceptions/AlertError.php
index 274bb73c56..1b45b74ed4 100644
--- a/system/Exceptions/AlertError.php
+++ b/system/Exceptions/AlertError.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/CastException.php b/system/Exceptions/CastException.php
index 8dfb29543a..139c1c5fc7 100644
--- a/system/Exceptions/CastException.php
+++ b/system/Exceptions/CastException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/ConfigException.php b/system/Exceptions/ConfigException.php
index 6eea2638c5..d8849b809c 100644
--- a/system/Exceptions/ConfigException.php
+++ b/system/Exceptions/ConfigException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/CriticalError.php b/system/Exceptions/CriticalError.php
index b5129bde0c..756393d5d9 100644
--- a/system/Exceptions/CriticalError.php
+++ b/system/Exceptions/CriticalError.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/DebugTraceableTrait.php b/system/Exceptions/DebugTraceableTrait.php
index b5fb691d78..e8f204ac41 100644
--- a/system/Exceptions/DebugTraceableTrait.php
+++ b/system/Exceptions/DebugTraceableTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/DownloadException.php b/system/Exceptions/DownloadException.php
index 5626cfefa8..df78127d6d 100644
--- a/system/Exceptions/DownloadException.php
+++ b/system/Exceptions/DownloadException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/EmergencyError.php b/system/Exceptions/EmergencyError.php
index db3e25e668..76577ac79b 100644
--- a/system/Exceptions/EmergencyError.php
+++ b/system/Exceptions/EmergencyError.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/ExceptionInterface.php b/system/Exceptions/ExceptionInterface.php
index be8ac69266..27b9c2faf5 100644
--- a/system/Exceptions/ExceptionInterface.php
+++ b/system/Exceptions/ExceptionInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/FrameworkException.php b/system/Exceptions/FrameworkException.php
index faf3f14801..a7d8fe0315 100644
--- a/system/Exceptions/FrameworkException.php
+++ b/system/Exceptions/FrameworkException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/HTTPExceptionInterface.php b/system/Exceptions/HTTPExceptionInterface.php
index 901f0b6ca3..1974d63af6 100644
--- a/system/Exceptions/HTTPExceptionInterface.php
+++ b/system/Exceptions/HTTPExceptionInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/HasExitCodeInterface.php b/system/Exceptions/HasExitCodeInterface.php
index 3380d00b81..1557c82ad6 100644
--- a/system/Exceptions/HasExitCodeInterface.php
+++ b/system/Exceptions/HasExitCodeInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/ModelException.php b/system/Exceptions/ModelException.php
index 39590a60ea..a92e388b4d 100644
--- a/system/Exceptions/ModelException.php
+++ b/system/Exceptions/ModelException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/PageNotFoundException.php b/system/Exceptions/PageNotFoundException.php
index 69e93f9b9b..b1af079e3a 100644
--- a/system/Exceptions/PageNotFoundException.php
+++ b/system/Exceptions/PageNotFoundException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Exceptions/TestException.php b/system/Exceptions/TestException.php
index dadbbc002b..f533dc2793 100644
--- a/system/Exceptions/TestException.php
+++ b/system/Exceptions/TestException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Files/Exceptions/FileException.php b/system/Files/Exceptions/FileException.php
index b877bad279..5feb97929e 100644
--- a/system/Files/Exceptions/FileException.php
+++ b/system/Files/Exceptions/FileException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Files/Exceptions/FileNotFoundException.php b/system/Files/Exceptions/FileNotFoundException.php
index 1c0f4cfd22..86b22625aa 100644
--- a/system/Files/Exceptions/FileNotFoundException.php
+++ b/system/Files/Exceptions/FileNotFoundException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Files/File.php b/system/Files/File.php
index 4e4ee38804..ddf33ed330 100644
--- a/system/Files/File.php
+++ b/system/Files/File.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Files/FileCollection.php b/system/Files/FileCollection.php
index 87f987eb8f..5f88aa4944 100644
--- a/system/Files/FileCollection.php
+++ b/system/Files/FileCollection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Filters/CSRF.php b/system/Filters/CSRF.php
index 23e6e2540e..501d09704e 100644
--- a/system/Filters/CSRF.php
+++ b/system/Filters/CSRF.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Filters/DebugToolbar.php b/system/Filters/DebugToolbar.php
index 75662d841a..69e6237993 100644
--- a/system/Filters/DebugToolbar.php
+++ b/system/Filters/DebugToolbar.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Filters/Exceptions/FilterException.php b/system/Filters/Exceptions/FilterException.php
index 04bb36bdc2..1226ba3184 100644
--- a/system/Filters/Exceptions/FilterException.php
+++ b/system/Filters/Exceptions/FilterException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Filters/FilterInterface.php b/system/Filters/FilterInterface.php
index 1a3363c908..98f45afb00 100644
--- a/system/Filters/FilterInterface.php
+++ b/system/Filters/FilterInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Filters/Filters.php b/system/Filters/Filters.php
index 25ca9a9ec5..8e0888e049 100644
--- a/system/Filters/Filters.php
+++ b/system/Filters/Filters.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Filters/Honeypot.php b/system/Filters/Honeypot.php
index e30e90f8d9..6f26fff598 100644
--- a/system/Filters/Honeypot.php
+++ b/system/Filters/Honeypot.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Filters/InvalidChars.php b/system/Filters/InvalidChars.php
index 93124fdb4e..b70efbc3b7 100644
--- a/system/Filters/InvalidChars.php
+++ b/system/Filters/InvalidChars.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Filters/SecureHeaders.php b/system/Filters/SecureHeaders.php
index 952926b957..cafc66c8f0 100644
--- a/system/Filters/SecureHeaders.php
+++ b/system/Filters/SecureHeaders.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Format/Exceptions/FormatException.php b/system/Format/Exceptions/FormatException.php
index 55c36d3d23..5a8c2d2cfe 100644
--- a/system/Format/Exceptions/FormatException.php
+++ b/system/Format/Exceptions/FormatException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Format/Format.php b/system/Format/Format.php
index 6b4eb73f1f..4a9cb60981 100644
--- a/system/Format/Format.php
+++ b/system/Format/Format.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Format/FormatterInterface.php b/system/Format/FormatterInterface.php
index 6e8e9bd503..0f005568c7 100644
--- a/system/Format/FormatterInterface.php
+++ b/system/Format/FormatterInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Format/JSONFormatter.php b/system/Format/JSONFormatter.php
index 3e708e9fa6..7d2ad5259c 100644
--- a/system/Format/JSONFormatter.php
+++ b/system/Format/JSONFormatter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Format/XMLFormatter.php b/system/Format/XMLFormatter.php
index f1513ef661..c85eae5fef 100644
--- a/system/Format/XMLFormatter.php
+++ b/system/Format/XMLFormatter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/CLIRequest.php b/system/HTTP/CLIRequest.php
index 900d4484ca..429538d70d 100644
--- a/system/HTTP/CLIRequest.php
+++ b/system/HTTP/CLIRequest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/CURLRequest.php b/system/HTTP/CURLRequest.php
index 35b62ec348..59ea328e6f 100644
--- a/system/HTTP/CURLRequest.php
+++ b/system/HTTP/CURLRequest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/ContentSecurityPolicy.php b/system/HTTP/ContentSecurityPolicy.php
index 6a3caed925..0e3b252dc7 100644
--- a/system/HTTP/ContentSecurityPolicy.php
+++ b/system/HTTP/ContentSecurityPolicy.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/DownloadResponse.php b/system/HTTP/DownloadResponse.php
index 14dc3fec14..a36c96e582 100644
--- a/system/HTTP/DownloadResponse.php
+++ b/system/HTTP/DownloadResponse.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Exceptions/HTTPException.php b/system/HTTP/Exceptions/HTTPException.php
index 32f9ceabd6..2fb450249a 100644
--- a/system/HTTP/Exceptions/HTTPException.php
+++ b/system/HTTP/Exceptions/HTTPException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Exceptions/RedirectException.php b/system/HTTP/Exceptions/RedirectException.php
index 605f40eaba..a574158cd4 100644
--- a/system/HTTP/Exceptions/RedirectException.php
+++ b/system/HTTP/Exceptions/RedirectException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Files/FileCollection.php b/system/HTTP/Files/FileCollection.php
index 7188d357b0..72644db6ed 100644
--- a/system/HTTP/Files/FileCollection.php
+++ b/system/HTTP/Files/FileCollection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Files/UploadedFile.php b/system/HTTP/Files/UploadedFile.php
index 70ece748d8..d993d6c91e 100644
--- a/system/HTTP/Files/UploadedFile.php
+++ b/system/HTTP/Files/UploadedFile.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Files/UploadedFileInterface.php b/system/HTTP/Files/UploadedFileInterface.php
index 170f81c2de..e828fa9fe5 100644
--- a/system/HTTP/Files/UploadedFileInterface.php
+++ b/system/HTTP/Files/UploadedFileInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Header.php b/system/HTTP/Header.php
index b152509a1c..10cbf1b6ce 100644
--- a/system/HTTP/Header.php
+++ b/system/HTTP/Header.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/IncomingRequest.php b/system/HTTP/IncomingRequest.php
index ee5aa8bd6c..f2bc71e8e1 100755
--- a/system/HTTP/IncomingRequest.php
+++ b/system/HTTP/IncomingRequest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Message.php b/system/HTTP/Message.php
index 6de3835ddc..71c4429f28 100644
--- a/system/HTTP/Message.php
+++ b/system/HTTP/Message.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/MessageInterface.php b/system/HTTP/MessageInterface.php
index 04a286fad9..b8850a0ffb 100644
--- a/system/HTTP/MessageInterface.php
+++ b/system/HTTP/MessageInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/MessageTrait.php b/system/HTTP/MessageTrait.php
index 85280da092..2f6e57a90c 100644
--- a/system/HTTP/MessageTrait.php
+++ b/system/HTTP/MessageTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Negotiate.php b/system/HTTP/Negotiate.php
index b1d5fdfa93..d5a6fbffd8 100644
--- a/system/HTTP/Negotiate.php
+++ b/system/HTTP/Negotiate.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/OutgoingRequest.php b/system/HTTP/OutgoingRequest.php
index b6f733f5ea..27e473a59a 100644
--- a/system/HTTP/OutgoingRequest.php
+++ b/system/HTTP/OutgoingRequest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/OutgoingRequestInterface.php b/system/HTTP/OutgoingRequestInterface.php
index b4a62dfde7..da9e36206c 100644
--- a/system/HTTP/OutgoingRequestInterface.php
+++ b/system/HTTP/OutgoingRequestInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/RedirectResponse.php b/system/HTTP/RedirectResponse.php
index 8efd4c2c51..5ce1d83b92 100644
--- a/system/HTTP/RedirectResponse.php
+++ b/system/HTTP/RedirectResponse.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Request.php b/system/HTTP/Request.php
index 1466175c7b..007b0fcc56 100644
--- a/system/HTTP/Request.php
+++ b/system/HTTP/Request.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/RequestInterface.php b/system/HTTP/RequestInterface.php
index cb55ccb5bf..26af51df9d 100644
--- a/system/HTTP/RequestInterface.php
+++ b/system/HTTP/RequestInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/RequestTrait.php b/system/HTTP/RequestTrait.php
index 6db903ddac..c660aaa141 100644
--- a/system/HTTP/RequestTrait.php
+++ b/system/HTTP/RequestTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/ResponsableInterface.php b/system/HTTP/ResponsableInterface.php
index 0cca5356f1..41bff03909 100644
--- a/system/HTTP/ResponsableInterface.php
+++ b/system/HTTP/ResponsableInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/Response.php b/system/HTTP/Response.php
index a061544e9f..8c935225ae 100644
--- a/system/HTTP/Response.php
+++ b/system/HTTP/Response.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/ResponseInterface.php b/system/HTTP/ResponseInterface.php
index a109f31529..c3aff64711 100644
--- a/system/HTTP/ResponseInterface.php
+++ b/system/HTTP/ResponseInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/ResponseTrait.php b/system/HTTP/ResponseTrait.php
index e5e006c776..a92273a2a6 100644
--- a/system/HTTP/ResponseTrait.php
+++ b/system/HTTP/ResponseTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/SiteURI.php b/system/HTTP/SiteURI.php
index 6d56507314..139b7c32c5 100644
--- a/system/HTTP/SiteURI.php
+++ b/system/HTTP/SiteURI.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/SiteURIFactory.php b/system/HTTP/SiteURIFactory.php
index 36b9d705b2..e0c20b6174 100644
--- a/system/HTTP/SiteURIFactory.php
+++ b/system/HTTP/SiteURIFactory.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/URI.php b/system/HTTP/URI.php
index 608f8b75d5..549659e573 100644
--- a/system/HTTP/URI.php
+++ b/system/HTTP/URI.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HTTP/UserAgent.php b/system/HTTP/UserAgent.php
index 77e7cb4392..f490091255 100644
--- a/system/HTTP/UserAgent.php
+++ b/system/HTTP/UserAgent.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/array_helper.php b/system/Helpers/array_helper.php
index 6d501e2732..378e5840da 100644
--- a/system/Helpers/array_helper.php
+++ b/system/Helpers/array_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/cookie_helper.php b/system/Helpers/cookie_helper.php
index 7646693266..aa6ae2eb21 100755
--- a/system/Helpers/cookie_helper.php
+++ b/system/Helpers/cookie_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/date_helper.php b/system/Helpers/date_helper.php
index ba9c9a2494..f128bf2bc5 100644
--- a/system/Helpers/date_helper.php
+++ b/system/Helpers/date_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/filesystem_helper.php b/system/Helpers/filesystem_helper.php
index 47c829bbc3..bcc4b124f8 100644
--- a/system/Helpers/filesystem_helper.php
+++ b/system/Helpers/filesystem_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/form_helper.php b/system/Helpers/form_helper.php
index 7edb05cf1d..25243d5b8f 100644
--- a/system/Helpers/form_helper.php
+++ b/system/Helpers/form_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/html_helper.php b/system/Helpers/html_helper.php
index 7a76434d0e..952225cf89 100755
--- a/system/Helpers/html_helper.php
+++ b/system/Helpers/html_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/inflector_helper.php b/system/Helpers/inflector_helper.php
index bac5ab1e2d..abc565652e 100755
--- a/system/Helpers/inflector_helper.php
+++ b/system/Helpers/inflector_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/kint_helper.php b/system/Helpers/kint_helper.php
index 4221573a2c..075c162315 100644
--- a/system/Helpers/kint_helper.php
+++ b/system/Helpers/kint_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/number_helper.php b/system/Helpers/number_helper.php
index 1b97d9a360..d88d7b961f 100644
--- a/system/Helpers/number_helper.php
+++ b/system/Helpers/number_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/security_helper.php b/system/Helpers/security_helper.php
index eba12de59a..b2cc833865 100644
--- a/system/Helpers/security_helper.php
+++ b/system/Helpers/security_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/test_helper.php b/system/Helpers/test_helper.php
index a542bb1ca7..f86ca468b0 100644
--- a/system/Helpers/test_helper.php
+++ b/system/Helpers/test_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/text_helper.php b/system/Helpers/text_helper.php
index 48e013826a..6cbbb0bb83 100755
--- a/system/Helpers/text_helper.php
+++ b/system/Helpers/text_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/url_helper.php b/system/Helpers/url_helper.php
index 27e3ce1d07..7781ad511c 100644
--- a/system/Helpers/url_helper.php
+++ b/system/Helpers/url_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Helpers/xml_helper.php b/system/Helpers/xml_helper.php
index ece2820137..13f9c0dfa5 100644
--- a/system/Helpers/xml_helper.php
+++ b/system/Helpers/xml_helper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Honeypot/Exceptions/HoneypotException.php b/system/Honeypot/Exceptions/HoneypotException.php
index 31d13151e9..ce743b8651 100644
--- a/system/Honeypot/Exceptions/HoneypotException.php
+++ b/system/Honeypot/Exceptions/HoneypotException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Honeypot/Honeypot.php b/system/Honeypot/Honeypot.php
index 82da90020c..e0879f157e 100644
--- a/system/Honeypot/Honeypot.php
+++ b/system/Honeypot/Honeypot.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HotReloader/DirectoryHasher.php b/system/HotReloader/DirectoryHasher.php
index ba8d2bfbb8..0910f2fa94 100644
--- a/system/HotReloader/DirectoryHasher.php
+++ b/system/HotReloader/DirectoryHasher.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HotReloader/HotReloader.php b/system/HotReloader/HotReloader.php
index 579bcd4ac5..6dfd0fcf66 100644
--- a/system/HotReloader/HotReloader.php
+++ b/system/HotReloader/HotReloader.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/HotReloader/IteratorFilter.php b/system/HotReloader/IteratorFilter.php
index db775f9006..983e1297a7 100644
--- a/system/HotReloader/IteratorFilter.php
+++ b/system/HotReloader/IteratorFilter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/I18n/Exceptions/I18nException.php b/system/I18n/Exceptions/I18nException.php
index a0af507828..79c9e8326a 100644
--- a/system/I18n/Exceptions/I18nException.php
+++ b/system/I18n/Exceptions/I18nException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/I18n/Time.php b/system/I18n/Time.php
index 520f38eb90..8f6aa80c3d 100644
--- a/system/I18n/Time.php
+++ b/system/I18n/Time.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/I18n/TimeDifference.php b/system/I18n/TimeDifference.php
index c797a422d8..81ca92be6a 100644
--- a/system/I18n/TimeDifference.php
+++ b/system/I18n/TimeDifference.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/I18n/TimeLegacy.php b/system/I18n/TimeLegacy.php
index 7be9f80fac..0fc6f8de15 100644
--- a/system/I18n/TimeLegacy.php
+++ b/system/I18n/TimeLegacy.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/I18n/TimeTrait.php b/system/I18n/TimeTrait.php
index ee491f2bc3..65cae02bef 100644
--- a/system/I18n/TimeTrait.php
+++ b/system/I18n/TimeTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Images/Exceptions/ImageException.php b/system/Images/Exceptions/ImageException.php
index e72a19f8b6..93491bfa9e 100644
--- a/system/Images/Exceptions/ImageException.php
+++ b/system/Images/Exceptions/ImageException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Images/Handlers/BaseHandler.php b/system/Images/Handlers/BaseHandler.php
index fef31755aa..c9b781396c 100644
--- a/system/Images/Handlers/BaseHandler.php
+++ b/system/Images/Handlers/BaseHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Images/Handlers/GDHandler.php b/system/Images/Handlers/GDHandler.php
index 6620dcac43..0170c3ed81 100644
--- a/system/Images/Handlers/GDHandler.php
+++ b/system/Images/Handlers/GDHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Images/Handlers/ImageMagickHandler.php b/system/Images/Handlers/ImageMagickHandler.php
index 857a273d53..f63919147f 100644
--- a/system/Images/Handlers/ImageMagickHandler.php
+++ b/system/Images/Handlers/ImageMagickHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Images/Image.php b/system/Images/Image.php
index 291ad002a6..a2cf514361 100644
--- a/system/Images/Image.php
+++ b/system/Images/Image.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Images/ImageHandlerInterface.php b/system/Images/ImageHandlerInterface.php
index 1c3593a99b..a4603078d8 100644
--- a/system/Images/ImageHandlerInterface.php
+++ b/system/Images/ImageHandlerInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/Language.php b/system/Language/Language.php
index 8633f8a2dd..078777dd15 100644
--- a/system/Language/Language.php
+++ b/system/Language/Language.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/CLI.php b/system/Language/en/CLI.php
index edef33a7d1..16f34482c7 100644
--- a/system/Language/en/CLI.php
+++ b/system/Language/en/CLI.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Cache.php b/system/Language/en/Cache.php
index d2abc9bedb..b877c9bbaa 100644
--- a/system/Language/en/Cache.php
+++ b/system/Language/en/Cache.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Cast.php b/system/Language/en/Cast.php
index 46132b0ec8..04ff1ef9e1 100644
--- a/system/Language/en/Cast.php
+++ b/system/Language/en/Cast.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Cookie.php b/system/Language/en/Cookie.php
index 3de21a0fda..c880f03293 100644
--- a/system/Language/en/Cookie.php
+++ b/system/Language/en/Cookie.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Core.php b/system/Language/en/Core.php
index 1adfbe4465..c01d43a9a2 100644
--- a/system/Language/en/Core.php
+++ b/system/Language/en/Core.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Database.php b/system/Language/en/Database.php
index f0410e744a..c5a5ddc854 100644
--- a/system/Language/en/Database.php
+++ b/system/Language/en/Database.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Email.php b/system/Language/en/Email.php
index 6938b16ba1..23a97a75f2 100644
--- a/system/Language/en/Email.php
+++ b/system/Language/en/Email.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Encryption.php b/system/Language/en/Encryption.php
index c0e7cb8276..dee023a373 100644
--- a/system/Language/en/Encryption.php
+++ b/system/Language/en/Encryption.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Errors.php b/system/Language/en/Errors.php
index 55a130a998..29d6ad3646 100644
--- a/system/Language/en/Errors.php
+++ b/system/Language/en/Errors.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Fabricator.php b/system/Language/en/Fabricator.php
index bfedec747d..e9991f9c07 100644
--- a/system/Language/en/Fabricator.php
+++ b/system/Language/en/Fabricator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Files.php b/system/Language/en/Files.php
index 4506abe686..66b8c550b5 100644
--- a/system/Language/en/Files.php
+++ b/system/Language/en/Files.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Filters.php b/system/Language/en/Filters.php
index aca478cef9..811397006c 100644
--- a/system/Language/en/Filters.php
+++ b/system/Language/en/Filters.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Format.php b/system/Language/en/Format.php
index 7c54534270..7d792e2b61 100644
--- a/system/Language/en/Format.php
+++ b/system/Language/en/Format.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/HTTP.php b/system/Language/en/HTTP.php
index e9082f85d1..11cb188439 100644
--- a/system/Language/en/HTTP.php
+++ b/system/Language/en/HTTP.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Images.php b/system/Language/en/Images.php
index be4d52903c..41dbe973aa 100644
--- a/system/Language/en/Images.php
+++ b/system/Language/en/Images.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Language.php b/system/Language/en/Language.php
index 80920b2f16..16456c3cc4 100644
--- a/system/Language/en/Language.php
+++ b/system/Language/en/Language.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Log.php b/system/Language/en/Log.php
index d6ee779a5f..0a8f274ba0 100644
--- a/system/Language/en/Log.php
+++ b/system/Language/en/Log.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Migrations.php b/system/Language/en/Migrations.php
index 9bfb5c60ae..5d7f3a8654 100644
--- a/system/Language/en/Migrations.php
+++ b/system/Language/en/Migrations.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Number.php b/system/Language/en/Number.php
index c1660fdd49..760d171f5d 100644
--- a/system/Language/en/Number.php
+++ b/system/Language/en/Number.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Pager.php b/system/Language/en/Pager.php
index 884ea8e05a..f5dd6f05e9 100644
--- a/system/Language/en/Pager.php
+++ b/system/Language/en/Pager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Publisher.php b/system/Language/en/Publisher.php
index 3eb74a3f20..eb18dfebd5 100644
--- a/system/Language/en/Publisher.php
+++ b/system/Language/en/Publisher.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/RESTful.php b/system/Language/en/RESTful.php
index b3ac05e89b..59e014b72f 100644
--- a/system/Language/en/RESTful.php
+++ b/system/Language/en/RESTful.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Router.php b/system/Language/en/Router.php
index cb90612abd..7bb5586019 100644
--- a/system/Language/en/Router.php
+++ b/system/Language/en/Router.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Security.php b/system/Language/en/Security.php
index d7f8a652e0..145abaab71 100644
--- a/system/Language/en/Security.php
+++ b/system/Language/en/Security.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Session.php b/system/Language/en/Session.php
index 2eff09e615..340ef752c3 100644
--- a/system/Language/en/Session.php
+++ b/system/Language/en/Session.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Test.php b/system/Language/en/Test.php
index d54b9188a6..8abcfc3486 100644
--- a/system/Language/en/Test.php
+++ b/system/Language/en/Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Time.php b/system/Language/en/Time.php
index decee74fb8..2cb25218a1 100644
--- a/system/Language/en/Time.php
+++ b/system/Language/en/Time.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/Validation.php b/system/Language/en/Validation.php
index 2a980ba4c5..ba5b413e79 100644
--- a/system/Language/en/Validation.php
+++ b/system/Language/en/Validation.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Language/en/View.php b/system/Language/en/View.php
index cd6b6c294a..79d57f06b9 100644
--- a/system/Language/en/View.php
+++ b/system/Language/en/View.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Log/Exceptions/LogException.php b/system/Log/Exceptions/LogException.php
index c5f8b97999..1a2f1a7b99 100644
--- a/system/Log/Exceptions/LogException.php
+++ b/system/Log/Exceptions/LogException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Log/Handlers/BaseHandler.php b/system/Log/Handlers/BaseHandler.php
index c19ecb0b80..34f9fe2ecd 100644
--- a/system/Log/Handlers/BaseHandler.php
+++ b/system/Log/Handlers/BaseHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Log/Handlers/ChromeLoggerHandler.php b/system/Log/Handlers/ChromeLoggerHandler.php
index b04d6f6923..32d93b8964 100644
--- a/system/Log/Handlers/ChromeLoggerHandler.php
+++ b/system/Log/Handlers/ChromeLoggerHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Log/Handlers/ErrorlogHandler.php b/system/Log/Handlers/ErrorlogHandler.php
index d9f3fc4e0a..c9a48061df 100644
--- a/system/Log/Handlers/ErrorlogHandler.php
+++ b/system/Log/Handlers/ErrorlogHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Log/Handlers/FileHandler.php b/system/Log/Handlers/FileHandler.php
index 88e384781a..aaf8899da3 100644
--- a/system/Log/Handlers/FileHandler.php
+++ b/system/Log/Handlers/FileHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Log/Handlers/HandlerInterface.php b/system/Log/Handlers/HandlerInterface.php
index 7b809a320d..40a9958c71 100644
--- a/system/Log/Handlers/HandlerInterface.php
+++ b/system/Log/Handlers/HandlerInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Log/Logger.php b/system/Log/Logger.php
index 2c17ded5f7..e51e306768 100644
--- a/system/Log/Logger.php
+++ b/system/Log/Logger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Model.php b/system/Model.php
index b64c8225e1..7cb652e2a6 100644
--- a/system/Model.php
+++ b/system/Model.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Modules/Modules.php b/system/Modules/Modules.php
index e17b9f3c24..ca4fe40ab1 100644
--- a/system/Modules/Modules.php
+++ b/system/Modules/Modules.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Pager/Exceptions/PagerException.php b/system/Pager/Exceptions/PagerException.php
index 6f1032f728..b87c9f9940 100644
--- a/system/Pager/Exceptions/PagerException.php
+++ b/system/Pager/Exceptions/PagerException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Pager/Pager.php b/system/Pager/Pager.php
index b08cb00410..7971117d8c 100644
--- a/system/Pager/Pager.php
+++ b/system/Pager/Pager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Pager/PagerInterface.php b/system/Pager/PagerInterface.php
index 84018d7ac5..650b04f48e 100644
--- a/system/Pager/PagerInterface.php
+++ b/system/Pager/PagerInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Pager/PagerRenderer.php b/system/Pager/PagerRenderer.php
index 454ac9f1cd..42a12a3594 100644
--- a/system/Pager/PagerRenderer.php
+++ b/system/Pager/PagerRenderer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Publisher/ContentReplacer.php b/system/Publisher/ContentReplacer.php
index accfdd7166..72dd8ace43 100644
--- a/system/Publisher/ContentReplacer.php
+++ b/system/Publisher/ContentReplacer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Publisher/Exceptions/PublisherException.php b/system/Publisher/Exceptions/PublisherException.php
index 5204897c97..e26a55975d 100644
--- a/system/Publisher/Exceptions/PublisherException.php
+++ b/system/Publisher/Exceptions/PublisherException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Publisher/Publisher.php b/system/Publisher/Publisher.php
index 589e88381e..5f46584516 100644
--- a/system/Publisher/Publisher.php
+++ b/system/Publisher/Publisher.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/RESTful/BaseResource.php b/system/RESTful/BaseResource.php
index 1c21f65da8..d14d1e2637 100644
--- a/system/RESTful/BaseResource.php
+++ b/system/RESTful/BaseResource.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/RESTful/ResourceController.php b/system/RESTful/ResourceController.php
index 03ba4d3146..eb15751fb5 100644
--- a/system/RESTful/ResourceController.php
+++ b/system/RESTful/ResourceController.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/RESTful/ResourcePresenter.php b/system/RESTful/ResourcePresenter.php
index 8c39bd8a00..00bd54ed03 100644
--- a/system/RESTful/ResourcePresenter.php
+++ b/system/RESTful/ResourcePresenter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/AutoRouter.php b/system/Router/AutoRouter.php
index 281b8a4973..5e88082e8c 100644
--- a/system/Router/AutoRouter.php
+++ b/system/Router/AutoRouter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/AutoRouterImproved.php b/system/Router/AutoRouterImproved.php
index a86e92f016..624a1c3fd7 100644
--- a/system/Router/AutoRouterImproved.php
+++ b/system/Router/AutoRouterImproved.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/AutoRouterInterface.php b/system/Router/AutoRouterInterface.php
index 6d98aec4a5..7edec821db 100644
--- a/system/Router/AutoRouterInterface.php
+++ b/system/Router/AutoRouterInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/DefinedRouteCollector.php b/system/Router/DefinedRouteCollector.php
index 598efa6bb4..47ce7aa925 100644
--- a/system/Router/DefinedRouteCollector.php
+++ b/system/Router/DefinedRouteCollector.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/Exceptions/MethodNotFoundException.php b/system/Router/Exceptions/MethodNotFoundException.php
index d9ad45a5fa..6e82fb0958 100644
--- a/system/Router/Exceptions/MethodNotFoundException.php
+++ b/system/Router/Exceptions/MethodNotFoundException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/Exceptions/RedirectException.php b/system/Router/Exceptions/RedirectException.php
index 5e19e2e9ac..4baef3278d 100644
--- a/system/Router/Exceptions/RedirectException.php
+++ b/system/Router/Exceptions/RedirectException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/Exceptions/RouterException.php b/system/Router/Exceptions/RouterException.php
index 5a510e4716..fe21b53d32 100644
--- a/system/Router/Exceptions/RouterException.php
+++ b/system/Router/Exceptions/RouterException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/RouteCollection.php b/system/Router/RouteCollection.php
index 47ac4b63b6..58b9f98e59 100644
--- a/system/Router/RouteCollection.php
+++ b/system/Router/RouteCollection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/RouteCollectionInterface.php b/system/Router/RouteCollectionInterface.php
index 00f1d4c8bd..cff502aae7 100644
--- a/system/Router/RouteCollectionInterface.php
+++ b/system/Router/RouteCollectionInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/Router.php b/system/Router/Router.php
index e00031feb2..499cae70a4 100644
--- a/system/Router/Router.php
+++ b/system/Router/Router.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Router/RouterInterface.php b/system/Router/RouterInterface.php
index ffed59ca8a..ef84eeade8 100644
--- a/system/Router/RouterInterface.php
+++ b/system/Router/RouterInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Security/Exceptions/SecurityException.php b/system/Security/Exceptions/SecurityException.php
index ab2f6adc7f..16383fc25b 100644
--- a/system/Security/Exceptions/SecurityException.php
+++ b/system/Security/Exceptions/SecurityException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Security/Security.php b/system/Security/Security.php
index 9c28b82335..c96ff56efb 100644
--- a/system/Security/Security.php
+++ b/system/Security/Security.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Security/SecurityInterface.php b/system/Security/SecurityInterface.php
index af731e8278..a4124b8031 100644
--- a/system/Security/SecurityInterface.php
+++ b/system/Security/SecurityInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Exceptions/SessionException.php b/system/Session/Exceptions/SessionException.php
index af619c2c19..2a72a8f3ca 100644
--- a/system/Session/Exceptions/SessionException.php
+++ b/system/Session/Exceptions/SessionException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Handlers/ArrayHandler.php b/system/Session/Handlers/ArrayHandler.php
index 31951a788e..8faa00fdc9 100644
--- a/system/Session/Handlers/ArrayHandler.php
+++ b/system/Session/Handlers/ArrayHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Handlers/BaseHandler.php b/system/Session/Handlers/BaseHandler.php
index 086cdc2f22..00590b8711 100644
--- a/system/Session/Handlers/BaseHandler.php
+++ b/system/Session/Handlers/BaseHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Handlers/Database/MySQLiHandler.php b/system/Session/Handlers/Database/MySQLiHandler.php
index 380041aab6..a15f17bc90 100644
--- a/system/Session/Handlers/Database/MySQLiHandler.php
+++ b/system/Session/Handlers/Database/MySQLiHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Handlers/Database/PostgreHandler.php b/system/Session/Handlers/Database/PostgreHandler.php
index 0c140fea70..b92ab1e573 100644
--- a/system/Session/Handlers/Database/PostgreHandler.php
+++ b/system/Session/Handlers/Database/PostgreHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Handlers/DatabaseHandler.php b/system/Session/Handlers/DatabaseHandler.php
index edde55ca34..2d1d2fbbe9 100644
--- a/system/Session/Handlers/DatabaseHandler.php
+++ b/system/Session/Handlers/DatabaseHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Handlers/FileHandler.php b/system/Session/Handlers/FileHandler.php
index 9eb6424083..0f399b7cb2 100644
--- a/system/Session/Handlers/FileHandler.php
+++ b/system/Session/Handlers/FileHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Handlers/MemcachedHandler.php b/system/Session/Handlers/MemcachedHandler.php
index abccfafb5b..7984d9f7e6 100644
--- a/system/Session/Handlers/MemcachedHandler.php
+++ b/system/Session/Handlers/MemcachedHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Handlers/RedisHandler.php b/system/Session/Handlers/RedisHandler.php
index 690860c617..38955a50b7 100644
--- a/system/Session/Handlers/RedisHandler.php
+++ b/system/Session/Handlers/RedisHandler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/Session.php b/system/Session/Session.php
index 4e4a01581b..eae4f94ce9 100644
--- a/system/Session/Session.php
+++ b/system/Session/Session.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Session/SessionInterface.php b/system/Session/SessionInterface.php
index e78736bf34..53a95a47b0 100644
--- a/system/Session/SessionInterface.php
+++ b/system/Session/SessionInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Superglobals.php b/system/Superglobals.php
index c438635331..d804de2bc5 100644
--- a/system/Superglobals.php
+++ b/system/Superglobals.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/CIUnitTestCase.php b/system/Test/CIUnitTestCase.php
index 266a22b016..9bdb8ef825 100644
--- a/system/Test/CIUnitTestCase.php
+++ b/system/Test/CIUnitTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/ConfigFromArrayTrait.php b/system/Test/ConfigFromArrayTrait.php
index 17d2dd553c..3652fa1074 100644
--- a/system/Test/ConfigFromArrayTrait.php
+++ b/system/Test/ConfigFromArrayTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Constraints/SeeInDatabase.php b/system/Test/Constraints/SeeInDatabase.php
index dbed1e42de..31297f53a0 100644
--- a/system/Test/Constraints/SeeInDatabase.php
+++ b/system/Test/Constraints/SeeInDatabase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/ControllerTestTrait.php b/system/Test/ControllerTestTrait.php
index a99b899eaf..18a645d685 100644
--- a/system/Test/ControllerTestTrait.php
+++ b/system/Test/ControllerTestTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/DOMParser.php b/system/Test/DOMParser.php
index 1a2cbb0d61..8097c93d7a 100644
--- a/system/Test/DOMParser.php
+++ b/system/Test/DOMParser.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/DatabaseTestTrait.php b/system/Test/DatabaseTestTrait.php
index d7b8b02dda..d872785332 100644
--- a/system/Test/DatabaseTestTrait.php
+++ b/system/Test/DatabaseTestTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Fabricator.php b/system/Test/Fabricator.php
index 3a28f281d1..53af0a5157 100644
--- a/system/Test/Fabricator.php
+++ b/system/Test/Fabricator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/FeatureTestTrait.php b/system/Test/FeatureTestTrait.php
index c836326cc3..e5b54c5b01 100644
--- a/system/Test/FeatureTestTrait.php
+++ b/system/Test/FeatureTestTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/FilterTestTrait.php b/system/Test/FilterTestTrait.php
index 523717e546..ce60a49f48 100644
--- a/system/Test/FilterTestTrait.php
+++ b/system/Test/FilterTestTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Filters/CITestStreamFilter.php b/system/Test/Filters/CITestStreamFilter.php
index edcd4dbfd7..64c3d64d65 100644
--- a/system/Test/Filters/CITestStreamFilter.php
+++ b/system/Test/Filters/CITestStreamFilter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Interfaces/FabricatorModel.php b/system/Test/Interfaces/FabricatorModel.php
index 7173838a6a..d4a4c27091 100644
--- a/system/Test/Interfaces/FabricatorModel.php
+++ b/system/Test/Interfaces/FabricatorModel.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockAppConfig.php b/system/Test/Mock/MockAppConfig.php
index 0f1d5bf599..12c33ee2c6 100644
--- a/system/Test/Mock/MockAppConfig.php
+++ b/system/Test/Mock/MockAppConfig.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockAutoload.php b/system/Test/Mock/MockAutoload.php
index 291974c65b..033482926a 100644
--- a/system/Test/Mock/MockAutoload.php
+++ b/system/Test/Mock/MockAutoload.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockBuilder.php b/system/Test/Mock/MockBuilder.php
index ae28190b03..e947f0ef5f 100644
--- a/system/Test/Mock/MockBuilder.php
+++ b/system/Test/Mock/MockBuilder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockCLIConfig.php b/system/Test/Mock/MockCLIConfig.php
index a1756f41e2..c62df3d9f4 100644
--- a/system/Test/Mock/MockCLIConfig.php
+++ b/system/Test/Mock/MockCLIConfig.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockCURLRequest.php b/system/Test/Mock/MockCURLRequest.php
index 9ee38247ee..97f80e7c1d 100644
--- a/system/Test/Mock/MockCURLRequest.php
+++ b/system/Test/Mock/MockCURLRequest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockCache.php b/system/Test/Mock/MockCache.php
index 73a7558022..0e5ddcfd4c 100644
--- a/system/Test/Mock/MockCache.php
+++ b/system/Test/Mock/MockCache.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockCodeIgniter.php b/system/Test/Mock/MockCodeIgniter.php
index 200c92fa03..75de5d5722 100644
--- a/system/Test/Mock/MockCodeIgniter.php
+++ b/system/Test/Mock/MockCodeIgniter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockCommon.php b/system/Test/Mock/MockCommon.php
index d8ba461312..593ebdeede 100644
--- a/system/Test/Mock/MockCommon.php
+++ b/system/Test/Mock/MockCommon.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockConnection.php b/system/Test/Mock/MockConnection.php
index ea4ebac9b4..a046d4c7c0 100644
--- a/system/Test/Mock/MockConnection.php
+++ b/system/Test/Mock/MockConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockEmail.php b/system/Test/Mock/MockEmail.php
index 3683ee8885..222e77007c 100644
--- a/system/Test/Mock/MockEmail.php
+++ b/system/Test/Mock/MockEmail.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockEvents.php b/system/Test/Mock/MockEvents.php
index e4f556af81..9a2f0f35f3 100644
--- a/system/Test/Mock/MockEvents.php
+++ b/system/Test/Mock/MockEvents.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockFileLogger.php b/system/Test/Mock/MockFileLogger.php
index 7422221b68..8737e724b4 100644
--- a/system/Test/Mock/MockFileLogger.php
+++ b/system/Test/Mock/MockFileLogger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockIncomingRequest.php b/system/Test/Mock/MockIncomingRequest.php
index 03ab0d6c8b..f0c2ca3207 100644
--- a/system/Test/Mock/MockIncomingRequest.php
+++ b/system/Test/Mock/MockIncomingRequest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockLanguage.php b/system/Test/Mock/MockLanguage.php
index 267114e2a8..80143d555f 100644
--- a/system/Test/Mock/MockLanguage.php
+++ b/system/Test/Mock/MockLanguage.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockLogger.php b/system/Test/Mock/MockLogger.php
index 2ee2500b06..5130b2eaba 100644
--- a/system/Test/Mock/MockLogger.php
+++ b/system/Test/Mock/MockLogger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockQuery.php b/system/Test/Mock/MockQuery.php
index c67c4763af..61442494ba 100644
--- a/system/Test/Mock/MockQuery.php
+++ b/system/Test/Mock/MockQuery.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockResourceController.php b/system/Test/Mock/MockResourceController.php
index 2d5871f414..daf2cf4b92 100644
--- a/system/Test/Mock/MockResourceController.php
+++ b/system/Test/Mock/MockResourceController.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockResourcePresenter.php b/system/Test/Mock/MockResourcePresenter.php
index 26f0132391..9f6cd7ba16 100644
--- a/system/Test/Mock/MockResourcePresenter.php
+++ b/system/Test/Mock/MockResourcePresenter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockResponse.php b/system/Test/Mock/MockResponse.php
index 533129216b..ec3da86fd5 100755
--- a/system/Test/Mock/MockResponse.php
+++ b/system/Test/Mock/MockResponse.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockResult.php b/system/Test/Mock/MockResult.php
index 87654b1dd7..f3ca02651b 100644
--- a/system/Test/Mock/MockResult.php
+++ b/system/Test/Mock/MockResult.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockSecurity.php b/system/Test/Mock/MockSecurity.php
index a078154b7f..89d1eab0a7 100644
--- a/system/Test/Mock/MockSecurity.php
+++ b/system/Test/Mock/MockSecurity.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockSecurityConfig.php b/system/Test/Mock/MockSecurityConfig.php
index 001710494e..9b106d99f8 100644
--- a/system/Test/Mock/MockSecurityConfig.php
+++ b/system/Test/Mock/MockSecurityConfig.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockServices.php b/system/Test/Mock/MockServices.php
index f187004268..5d1076a6df 100644
--- a/system/Test/Mock/MockServices.php
+++ b/system/Test/Mock/MockServices.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockSession.php b/system/Test/Mock/MockSession.php
index 9f558e1034..c85fddb79a 100644
--- a/system/Test/Mock/MockSession.php
+++ b/system/Test/Mock/MockSession.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/Mock/MockTable.php b/system/Test/Mock/MockTable.php
index 697e72b12a..1976aaed7b 100644
--- a/system/Test/Mock/MockTable.php
+++ b/system/Test/Mock/MockTable.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/PhpStreamWrapper.php b/system/Test/PhpStreamWrapper.php
index 9ef3d7d439..980d5424ab 100644
--- a/system/Test/PhpStreamWrapper.php
+++ b/system/Test/PhpStreamWrapper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/ReflectionHelper.php b/system/Test/ReflectionHelper.php
index 4c25e3decd..c72276d1a0 100644
--- a/system/Test/ReflectionHelper.php
+++ b/system/Test/ReflectionHelper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/StreamFilterTrait.php b/system/Test/StreamFilterTrait.php
index 873576ec14..d8e00ac5c6 100644
--- a/system/Test/StreamFilterTrait.php
+++ b/system/Test/StreamFilterTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/TestLogger.php b/system/Test/TestLogger.php
index dce1277d98..7251d355a9 100644
--- a/system/Test/TestLogger.php
+++ b/system/Test/TestLogger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/TestResponse.php b/system/Test/TestResponse.php
index 12876681c2..44ee7a1bcc 100644
--- a/system/Test/TestResponse.php
+++ b/system/Test/TestResponse.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Test/bootstrap.php b/system/Test/bootstrap.php
index 3145725afe..188988e178 100644
--- a/system/Test/bootstrap.php
+++ b/system/Test/bootstrap.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Throttle/Throttler.php b/system/Throttle/Throttler.php
index 0a10c02335..44d12005a8 100644
--- a/system/Throttle/Throttler.php
+++ b/system/Throttle/Throttler.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Throttle/ThrottlerInterface.php b/system/Throttle/ThrottlerInterface.php
index 2fffcb7a4e..3bf7d35983 100644
--- a/system/Throttle/ThrottlerInterface.php
+++ b/system/Throttle/ThrottlerInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Traits/ConditionalTrait.php b/system/Traits/ConditionalTrait.php
index 620bdd8850..c739144dc8 100644
--- a/system/Traits/ConditionalTrait.php
+++ b/system/Traits/ConditionalTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Traits/PropertiesTrait.php b/system/Traits/PropertiesTrait.php
index 4983ed68f2..ed2da42efc 100644
--- a/system/Traits/PropertiesTrait.php
+++ b/system/Traits/PropertiesTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Typography/Typography.php b/system/Typography/Typography.php
index fd763cd52e..3931f9c9ec 100644
--- a/system/Typography/Typography.php
+++ b/system/Typography/Typography.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Validation/CreditCardRules.php b/system/Validation/CreditCardRules.php
index 61f59d7bfe..502ba1c913 100644
--- a/system/Validation/CreditCardRules.php
+++ b/system/Validation/CreditCardRules.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Validation/DotArrayFilter.php b/system/Validation/DotArrayFilter.php
index 43cb193707..18b4651aab 100644
--- a/system/Validation/DotArrayFilter.php
+++ b/system/Validation/DotArrayFilter.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Validation/Exceptions/ValidationException.php b/system/Validation/Exceptions/ValidationException.php
index 83772adb5a..06be287127 100644
--- a/system/Validation/Exceptions/ValidationException.php
+++ b/system/Validation/Exceptions/ValidationException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Validation/FileRules.php b/system/Validation/FileRules.php
index ce0ed8140d..a36e31872a 100644
--- a/system/Validation/FileRules.php
+++ b/system/Validation/FileRules.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Validation/FormatRules.php b/system/Validation/FormatRules.php
index 8a16c98e4a..d740371d86 100644
--- a/system/Validation/FormatRules.php
+++ b/system/Validation/FormatRules.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Validation/Rules.php b/system/Validation/Rules.php
index 0af5be8166..8542523a40 100644
--- a/system/Validation/Rules.php
+++ b/system/Validation/Rules.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Validation/Validation.php b/system/Validation/Validation.php
index ec835c5212..0f76f43e53 100644
--- a/system/Validation/Validation.php
+++ b/system/Validation/Validation.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/Validation/ValidationInterface.php b/system/Validation/ValidationInterface.php
index 78c38468dd..c4e07be3a4 100644
--- a/system/Validation/ValidationInterface.php
+++ b/system/Validation/ValidationInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/Cell.php b/system/View/Cell.php
index c5df775664..8796ab2b8d 100644
--- a/system/View/Cell.php
+++ b/system/View/Cell.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/Cells/Cell.php b/system/View/Cells/Cell.php
index 328bae1f89..f0297e31d9 100644
--- a/system/View/Cells/Cell.php
+++ b/system/View/Cells/Cell.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/Exceptions/ViewException.php b/system/View/Exceptions/ViewException.php
index 84ab72c544..baf6e5b069 100644
--- a/system/View/Exceptions/ViewException.php
+++ b/system/View/Exceptions/ViewException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/Filters.php b/system/View/Filters.php
index 379ccac186..b7367761f2 100644
--- a/system/View/Filters.php
+++ b/system/View/Filters.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/Parser.php b/system/View/Parser.php
index 62b63a1eaa..1a684a1d1e 100644
--- a/system/View/Parser.php
+++ b/system/View/Parser.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/Plugins.php b/system/View/Plugins.php
index 4b20caef8d..02a1bd4d30 100644
--- a/system/View/Plugins.php
+++ b/system/View/Plugins.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/RendererInterface.php b/system/View/RendererInterface.php
index a0f093b673..b759be412a 100644
--- a/system/View/RendererInterface.php
+++ b/system/View/RendererInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/Table.php b/system/View/Table.php
index 5e241f11fe..065f58bbbf 100644
--- a/system/View/Table.php
+++ b/system/View/Table.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/View.php b/system/View/View.php
index 6635a7edc0..e7135ea2ea 100644
--- a/system/View/View.php
+++ b/system/View/View.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/ViewDecoratorInterface.php b/system/View/ViewDecoratorInterface.php
index 0a4d99266c..71fb8824a5 100644
--- a/system/View/ViewDecoratorInterface.php
+++ b/system/View/ViewDecoratorInterface.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/View/ViewDecoratorTrait.php b/system/View/ViewDecoratorTrait.php
index 97cdbe0a25..9334c9c8f1 100644
--- a/system/View/ViewDecoratorTrait.php
+++ b/system/View/ViewDecoratorTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/system/bootstrap.php b/system/bootstrap.php
index 5d2ca0b225..e03fd570ca 100644
--- a/system/bootstrap.php
+++ b/system/bootstrap.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *
diff --git a/tests/_support/View/OtherCells/SampleClass.php b/tests/_support/View/OtherCells/SampleClass.php
index cff88bc58c..be7fc380ee 100644
--- a/tests/_support/View/OtherCells/SampleClass.php
+++ b/tests/_support/View/OtherCells/SampleClass.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * This file is part of CodeIgniter 4 framework.
  *