diff --git a/js/ui/lookingGlass.js b/js/ui/lookingGlass.js
index 4db755b95..ca827d870 100644
--- a/js/ui/lookingGlass.js
+++ b/js/ui/lookingGlass.js
@@ -159,7 +159,7 @@ function objectToString(o) {
         // special case this since the default is way, way too verbose
         return '<js function>';
     } else {
-        return o.toString();
+        return '' + o;
     }
 }