diff --git a/system/Language/en/Validation.php b/system/Language/en/Validation.php
index 2b870eb408..cc18664bd3 100644
--- a/system/Language/en/Validation.php
+++ b/system/Language/en/Validation.php
@@ -59,6 +59,7 @@ return [
     'valid_url'             => 'The {field} field must contain a valid URL.',
     'valid_url_strict'      => 'The {field} field must contain a valid URL.',
     'valid_date'            => 'The {field} field must contain a valid date.',
+    'valid_json'            => 'The {field} field must contain a valid json.',
 
     // Credit Cards
     'valid_cc_num' => '{field} does not appear to be a valid credit card number.',
diff --git a/tests/system/Language/LanguageTest.php b/tests/system/Language/LanguageTest.php
index 58994434b3..b2dbe07ec8 100644
--- a/tests/system/Language/LanguageTest.php
+++ b/tests/system/Language/LanguageTest.php
@@ -231,6 +231,7 @@ final class LanguageTest extends CIUnitTestCase
             ['RESTful'],
             ['Router'],
             ['Session'],
+            ['Test'],
             ['Time'],
             ['Validation'],
             ['View'],
diff --git a/user_guide_src/source/changelogs/v4.2.7.rst b/user_guide_src/source/changelogs/v4.2.7.rst
index b341ea5a0c..684a37b8c7 100644
--- a/user_guide_src/source/changelogs/v4.2.7.rst
+++ b/user_guide_src/source/changelogs/v4.2.7.rst
@@ -21,6 +21,11 @@ Enhancements
 
 none.
 
+Message Changes
+***************
+
+- Added missing item ``valid_json`` in ``Language/en/Validation.php``
+
 Changes
 *******