diff --git a/actions/attachment_thumbnail.php b/actions/attachment_thumbnail.php
index d1f9f2d00c..3b8eec3ca6 100644
--- a/actions/attachment_thumbnail.php
+++ b/actions/attachment_thumbnail.php
@@ -62,6 +62,6 @@ class Attachment_thumbnailAction extends AttachmentAction
             common_redirect($e->file->getUrl(), 302);
         }
 
-        common_redirect(File_thumbnail::url($thumbnail->filename));
+        common_redirect(File_thumbnail::url($thumbnail->filename), 302);
     }
 }