diff --git a/core/modules/system/system.services.yml b/core/modules/system/system.services.yml
index 1033fae..845b967 100644
--- a/core/modules/system/system.services.yml
+++ b/core/modules/system/system.services.yml
@@ -6,8 +6,8 @@ services:
   system.manager:
     class: Drupal\system\SystemManager
     arguments: ['@module_handler', '@database', '@entity.manager', '@request_stack']
-  tags:
-    - { name: backend_overridable }
+    tags:
+      - { name: backend_overridable }
   system.breadcrumb.default:
     class: Drupal\system\PathBasedBreadcrumbBuilder
     arguments: ['@router.request_context', '@access_manager', '@router', '@path_processor_manager', '@config.factory',  '@title_resolver', '@current_user']