diff --git a/admin/framework/composer.json b/admin/framework/composer.json
index 486cdf6787..8106c50078 100644
--- a/admin/framework/composer.json
+++ b/admin/framework/composer.json
@@ -38,6 +38,7 @@
         "ext-redis": "If you use Cache class RedisHandler",
         "ext-dom": "If you use TestResponse",
         "ext-libxml": "If you use TestResponse",
+        "ext-xdebug": "If you use CIUnitTestCase::assertHeaderEmitted()",
         "ext-fileinfo": "Improves mime type detection for files",
         "ext-readline": "Improves CLI::input() usability"
     },
diff --git a/composer.json b/composer.json
index da3d66ccda..364bbf2610 100644
--- a/composer.json
+++ b/composer.json
@@ -43,6 +43,7 @@
         "ext-redis": "If you use Cache class RedisHandler",
         "ext-dom": "If you use TestResponse",
         "ext-libxml": "If you use TestResponse",
+        "ext-xdebug": "If you use CIUnitTestCase::assertHeaderEmitted()",
         "ext-fileinfo": "Improves mime type detection for files",
         "ext-readline": "Improves CLI::input() usability"
     },