diff --git a/phpBB/config/default/container/services_auth.yml b/phpBB/config/default/container/services_auth.yml
index a0f9fbd8ef..ee6f7ef448 100644
--- a/phpBB/config/default/container/services_auth.yml
+++ b/phpBB/config/default/container/services_auth.yml
@@ -103,7 +103,7 @@ services:
     auth.provider.oauth.service.twitter:
         class: phpbb\auth\provider\oauth\service\twitter
         arguments:
-            - @config
-            - @request
+            - '@config'
+            - '@request'
         tags:
             - { name: auth.provider.oauth.service }
diff --git a/tests/di/fixtures/config/production/container/environment.yml b/tests/di/fixtures/config/production/container/environment.yml
index 9dcf11d865..4216b187cc 100644
--- a/tests/di/fixtures/config/production/container/environment.yml
+++ b/tests/di/fixtures/config/production/container/environment.yml
@@ -8,7 +8,7 @@ services:
     dbal.conn:
         class: phpbb\db\driver\factory
         arguments:
-            - @service_container
+            - '@service_container'
 
     dispatcher:
         class: phpbb\db\driver\container_mock
diff --git a/tests/di/fixtures/config/test/container/environment.yml b/tests/di/fixtures/config/test/container/environment.yml
index 14c986d123..7d528fed19 100644
--- a/tests/di/fixtures/config/test/container/environment.yml
+++ b/tests/di/fixtures/config/test/container/environment.yml
@@ -8,7 +8,7 @@ services:
     dbal.conn:
         class: phpbb\db\driver\factory
         arguments:
-            - @service_container
+            - '@service_container'
 
     dispatcher:
         class: phpbb\db\driver\container_mock
diff --git a/tests/di/fixtures/other_config/production/container/environment.yml b/tests/di/fixtures/other_config/production/container/environment.yml
index 4960562a6c..1170145b66 100644
--- a/tests/di/fixtures/other_config/production/container/environment.yml
+++ b/tests/di/fixtures/other_config/production/container/environment.yml
@@ -8,7 +8,7 @@ services:
     dbal.conn:
         class: phpbb\db\driver\factory
         arguments:
-            - @service_container
+            - '@service_container'
 
     dispatcher:
         class: phpbb\db\driver\container_mock
diff --git a/tests/di/fixtures/other_config/test/container/environment.yml b/tests/di/fixtures/other_config/test/container/environment.yml
index e285b1b781..6c36977d4d 100644
--- a/tests/di/fixtures/other_config/test/container/environment.yml
+++ b/tests/di/fixtures/other_config/test/container/environment.yml
@@ -8,7 +8,7 @@ services:
     dbal.conn:
         class: phpbb\db\driver\factory
         arguments:
-            - @service_container
+            - '@service_container'
 
     dispatcher:
         class: phpbb\db\driver\container_mock
diff --git a/tests/functional/fixtures/ext/foo/bar/config/services.yml b/tests/functional/fixtures/ext/foo/bar/config/services.yml
index d35be7955a..495c775a1f 100644
--- a/tests/functional/fixtures/ext/foo/bar/config/services.yml
+++ b/tests/functional/fixtures/ext/foo/bar/config/services.yml
@@ -2,13 +2,13 @@ services:
     foo_bar.controller:
         class: foo\bar\controller\controller
         arguments:
-            - @controller.helper
-            - @path_helper
-            - @template
-            - @config
-            - @user
-            - %core.root_path%
-            - %core.php_ext%
+            - '@controller.helper'
+            - '@path_helper'
+            - '@template'
+            - '@config'
+            - '@user'
+            - '%core.root_path%'
+            - '%core.php_ext%'
 
     foo_bar.listener.permission:
         class: foo\bar\event\permission