diff --git a/core/modules/system/tests/modules/theme_test/theme_test.services.yml b/core/modules/system/tests/modules/theme_test/theme_test.services.yml
index 482c219c73cfe42430dfddc3d732abbf5ad8e291..271fd4be92cecf5a429598759e5672b6a555b697 100644
--- a/core/modules/system/tests/modules/theme_test/theme_test.services.yml
+++ b/core/modules/system/tests/modules/theme_test/theme_test.services.yml
@@ -1,7 +1,7 @@
 services:
   theme_test.subscriber:
     class: Drupal\theme_test\EventSubscriber\ThemeTestSubscriber
-    arguments: [@current_route_match, @renderer]
+    arguments: ['@current_route_match', '@renderer']
     tags:
       - { name: event_subscriber }