--- a/browser/components/nsBrowserContentHandler.js
+++ b/browser/components/nsBrowserContentHandler.js
@@ -1,12 +1,14 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+/* eslint no-undef:2 */
+
 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 Components.utils.import("resource://gre/modules/Services.jsm");
 Components.utils.import("resource://gre/modules/AppConstants.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "LaterRun",
                                   "resource:///modules/LaterRun.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "PrivateBrowsingUtils",
                                   "resource://gre/modules/PrivateBrowsingUtils.jsm");
@@ -226,17 +228,17 @@ function openWindow(parent, url, target,
 function openPreferences() {
   var args = Components.classes["@mozilla.org/array;1"]
                      .createInstance(Components.interfaces.nsIMutableArray);
 
   var wuri = Components.classes["@mozilla.org/supports-string;1"]
                        .createInstance(Components.interfaces.nsISupportsString);
   wuri.data = "about:preferences";
 
-  sa.appendElement(wuri, /*weak =*/ false);
+  args.appendElement(wuri, /*weak =*/ false);
 
   Services.ww.openWindow(null, gBrowserContentHandler.chromeURL,
                          "_blank",
                          "chrome,dialog=no,all",
                          args);
 }
 
 function logSystemBasedSearch(engine) {