diff --git a/www/common/common-util.js b/www/common/common-util.js
index efcb46227..05da8bf93 100644
--- a/www/common/common-util.js
+++ b/www/common/common-util.js
@@ -36,6 +36,7 @@
     };
 
     Util.clone = function (o) {
+        if (o === undefined || o === null) { return o; }
         return JSON.parse(JSON.stringify(o));
     };