diff --git a/core/modules/system/tests/modules/ajax_test/ajax_test.routing.yml b/core/modules/system/tests/modules/ajax_test/ajax_test.routing.yml
index 3acb6f1..8be4f0a 100644
--- a/core/modules/system/tests/modules/ajax_test/ajax_test.routing.yml
+++ b/core/modules/system/tests/modules/ajax_test/ajax_test.routing.yml
@@ -3,7 +3,6 @@ ajax_test.dialog_contents:
   defaults:
     _title: 'AJAX Dialog contents'
     _content: '\Drupal\ajax_test\Controller\AjaxTestController::dialogContents'
-    _title: 'AJAX Dialog contents'
   requirements:
     _access: 'TRUE'