--- a/toolkit/components/url-classifier/tests/browser/browser_flash_block_lists.js
+++ b/toolkit/components/url-classifier/tests/browser/browser_flash_block_lists.js
@@ -1,13 +1,13 @@
 /* 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/. */
 "use strict";
-requestLongerTimeout(2);
+requestLongerTimeout(3);
 
 var {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
 
 Cu.import("resource://gre/modules/Task.jsm");
 Cc["@mozilla.org/moz/jssubscript-loader;1"]
   .getService(Ci.mozIJSSubScriptLoader)
   .loadSubScript("chrome://mochitests/content/browser/toolkit/components/url-classifier/tests/browser/classifierHelper.js",
                  this);