--- a/dom/voicemail/test/marionette/head.js
+++ b/dom/voicemail/test/marionette/head.js
@@ -1,17 +1,17 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
 const {Cc: Cc, Ci: Ci, Cr: Cr, Cu: Cu} = SpecialPowers;
 
-let RIL = {};
-Cu.import("resource://gre/modules/ril_consts.js", RIL);
+let RIL = SpecialPowers.wrap(SpecialPowers.createBlankObject());
+SpecialPowers.Cu.import("resource://gre/modules/ril_consts.js", RIL);
 
 // Emulate Promise.jsm semantics.
 Promise.defer = function() { return new Deferred(); }
 function Deferred()  {
   this.promise = new Promise(function(resolve, reject) {
     this.resolve = resolve;
     this.reject = reject;
   }.bind(this));