diff --git a/UI/Common/UIxFolderActions.m b/UI/Common/UIxFolderActions.m
index c41a342e1..2e3f1c3e9 100644
--- a/UI/Common/UIxFolderActions.m
+++ b/UI/Common/UIxFolderActions.m
@@ -499,7 +499,7 @@
   else
     response = [self responseWithStatus: 400
                   andJSONRepresentation: [NSDictionary dictionaryWithObject: @"missing 'uids' parameter"
-                                                                     forKey: @"error"]];
+                                                                     forKey: @"message"]];
   
   return response;
 }