diff --git a/www/common/userObject.js b/www/common/userObject.js
index 66d507a27..0acb44c68 100644
--- a/www/common/userObject.js
+++ b/www/common/userObject.js
@@ -727,7 +727,7 @@ define([
             parentEl[newName] = element;
             parentEl[oldName] = undefined;
             delete parentEl[oldName];
-            cb();
+            if (typeof cb === "function") { cb(); }
         };
 
         // REPLACE