diff --git a/Classes/Driver/AmazonS3Driver.php b/Classes/Driver/AmazonS3Driver.php
index c5577ebe..d1e4d3d2 100644
--- a/Classes/Driver/AmazonS3Driver.php
+++ b/Classes/Driver/AmazonS3Driver.php
@@ -786,7 +786,8 @@ public function getFolderInfoByIdentifier($folderIdentifier)
         return [
             'identifier' => $folderIdentifier,
             'name' => basename(rtrim($folderIdentifier, '/')),
-            'storage' => $this->storageUid
+            'storage' => $this->storageUid,
+            'mtime' => null,
         ];
     }