diff --git a/src/applications/doorkeeper/storage/DoorkeeperExternalObject.php b/src/applications/doorkeeper/storage/DoorkeeperExternalObject.php
index a6d4704a90..a4ce41adac 100644
--- a/src/applications/doorkeeper/storage/DoorkeeperExternalObject.php
+++ b/src/applications/doorkeeper/storage/DoorkeeperExternalObject.php
@@ -60,7 +60,11 @@ final class DoorkeeperExternalObject extends DoorkeeperDAO
   }
 
   public function getObjectKey() {
-    return $this->getRef()->getObjectKey();
+    $key = parent::getObjectKey();
+    if ($key === null) {
+      $key = $this->getRef()->getObjectKey();
+    }
+    return $key;
   }
 
   public function getRef() {