diff --git a/src/applications/doorkeeper/storage/DoorkeeperExternalObject.php b/src/applications/doorkeeper/storage/DoorkeeperExternalObject.php
--- a/src/applications/doorkeeper/storage/DoorkeeperExternalObject.php
+++ b/src/applications/doorkeeper/storage/DoorkeeperExternalObject.php
@@ -60,10 +60,7 @@
   }
 
   public function getObjectKey() {
-    $key = parent::getObjectKey();
-    if ($key === null) {
-      $key = $this->getRef()->getObjectKey();
-    }
+    $key = $this->getRef()->getObjectKey();
     return $key;
   }