diff --git a/core/modules/system/core.api.php b/core/modules/system/core.api.php
index 06762ac..2f951fe 100644
--- a/core/modules/system/core.api.php
+++ b/core/modules/system/core.api.php
@@ -820,7 +820,7 @@
  *   services are provided by other modules and not Drupal Core, you'll want
  *   these modules to be dependencies of your module.
  * - Add an entry to a modulename.services.yml file for the service. See
- *   @ref sec_discover above, or existing services.yml files in Core, for the
+ *   @ref sec_discover above, or existing *.services.yml files in Core, for the
  *   syntax; it will start with your machine name, refer to your default class,
  *   and list the services that need to be passed into your constructor.
  *