diff -u b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
--- b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
+++ b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
@@ -11,16 +11,16 @@
 use Drupal\Component\Serialization\Yaml;
 use Drupal\Core\Config\ConfigManagerInterface;
 use Drupal\Core\Config\StorageInterface;
-use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\system\FileDownloadController;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Drupal\Core\Config\StorageComparer;
+use Drupal\Core\Controller\ControllerBase;
 
 /**
  * Returns responses for config module routes.
  */
-class ConfigController implements ContainerInjectionInterface {
+class ConfigController extends ControllerBase {
 
   /**
    * The target storage.