diff -u b/core/modules/rest/src/Access/CSRFAccessCheck.php b/core/modules/rest/src/Access/CSRFAccessCheck.php
--- b/core/modules/rest/src/Access/CSRFAccessCheck.php
+++ b/core/modules/rest/src/Access/CSRFAccessCheck.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\rest\Access;
 
+use Drupal\Core\Access\AccessCheckInterface;
 use Drupal\Core\Routing\Access\AccessBase;
 use Drupal\Core\Session\AccountInterface;
 use Symfony\Component\Routing\Route;
@@ -15,7 +16,7 @@
 /**
  * Access protection against CSRF attacks.
  */
-class CSRFAccessCheck extends AccessBase {
+class CSRFAccessCheck extends AccessBase implements AccessCheckInterface {
 
   /**
    * Implements AccessCheckInterface::applies().