diff --git a/extensions/firefox/content/PdfStreamConverter.jsm b/extensions/firefox/content/PdfStreamConverter.jsm
index 1c2bb5257..e714c841e 100644
--- a/extensions/firefox/content/PdfStreamConverter.jsm
+++ b/extensions/firefox/content/PdfStreamConverter.jsm
@@ -114,6 +114,9 @@ function getStringPref(pref, def) {
 }
 
 function log(aMsg) {
+  if (!getBoolPref(PREF_PREFIX + '.pdfBugEnabled', false)) {
+    return;
+  }
   var msg = 'PdfStreamConverter.js: ' + (aMsg.join ? aMsg.join('') : aMsg);
   Services.console.logStringMessage(msg);
   dump(msg + '\n');
diff --git a/extensions/firefox/content/PdfjsChromeUtils.jsm b/extensions/firefox/content/PdfjsChromeUtils.jsm
index 89e995b3a..8b28ce45d 100644
--- a/extensions/firefox/content/PdfjsChromeUtils.jsm
+++ b/extensions/firefox/content/PdfjsChromeUtils.jsm
@@ -1,3 +1,5 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
 /* Copyright 2012 Mozilla Foundation
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,7 +25,7 @@ const Ci = Components.interfaces;
 const Cr = Components.results;
 const Cu = Components.utils;
 
-const PREF_PREFIX = 'pdfjs';
+const PREF_PREFIX = 'PDFJSSCRIPT_PREF_PREFIX';
 const PDF_CONTENT_TYPE = 'application/pdf';
 
 Cu.import('resource://gre/modules/XPCOMUtils.jsm');
@@ -175,8 +177,10 @@ let PdfjsChromeUtils = {
     return true;
   },
 
-  _isPrefAllowed: function (aPrefName) {
-    if (this._allowedPrefNames.indexOf(aPrefName) == -1) {
+  _ensurePreferenceAllowed: function (aPrefName) {
+    let unPrefixedName = aPrefName.split(PREF_PREFIX + '.');
+    if (unPrefixedName[0] !== '' ||
+        this._allowedPrefNames.indexOf(unPrefixedName[1]) === -1) {
       let msg = "'" + aPrefName + "' ";
       msg += "can't be accessed from content. See PdfjsChromeUtils." 
       throw new Error(msg);
@@ -184,27 +188,27 @@ let PdfjsChromeUtils = {
   },
 
   _clearUserPref: function (aPrefName) {
-    this._isPrefAllowed(aPrefName);
+    this._ensurePreferenceAllowed(aPrefName);
     Services.prefs.clearUserPref(aPrefName);
   },
 
   _setIntPref: function (aPrefName, aPrefValue) {
-    this._isPrefAllowed(aPrefName);
+    this._ensurePreferenceAllowed(aPrefName);
     Services.prefs.setIntPref(aPrefName, aPrefValue);
   },
 
   _setBoolPref: function (aPrefName, aPrefValue) {
-    this._isPrefAllowed(aPrefName);
+    this._ensurePreferenceAllowed(aPrefName);
     Services.prefs.setBoolPref(aPrefName, aPrefValue);
   },
 
   _setCharPref: function (aPrefName, aPrefValue) {
-    this._isPrefAllowed(aPrefName);
+    this._ensurePreferenceAllowed(aPrefName);
     Services.prefs.setCharPref(aPrefName, aPrefValue);
   },
 
   _setStringPref: function (aPrefName, aPrefValue) {
-    this._isPrefAllowed(aPrefName);
+    this._ensurePreferenceAllowed(aPrefName);
     let str = Cc['@mozilla.org/supports-string;1']
                 .createInstance(Ci.nsISupportsString);
     str.data = aPrefValue;
diff --git a/extensions/firefox/content/pdfjschildbootstrap.js b/extensions/firefox/content/pdfjschildbootstrap.js
index 8e5a48aa4..c9758b3e5 100644
--- a/extensions/firefox/content/pdfjschildbootstrap.js
+++ b/extensions/firefox/content/pdfjschildbootstrap.js
@@ -1,6 +1,19 @@
-/* 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/. */
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
+/* Copyright 2014 Mozilla Foundation
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
 /* jshint esnext:true */
 /* globals Components, PdfjsContentUtils, PdfJs */
 
diff --git a/make.js b/make.js
index 7ab11f765..f7789da8a 100644
--- a/make.js
+++ b/make.js
@@ -680,6 +680,8 @@ target.firefox = function() {
       FIREFOX_BUILD_CONTENT_DIR + 'PdfStreamConverter.jsm');
   sed('-i', /PDFJSSCRIPT_MOZ_CENTRAL/, 'false',
       FIREFOX_BUILD_CONTENT_DIR + 'PdfStreamConverter.jsm');
+  sed('-i', /PDFJSSCRIPT_PREF_PREFIX/, FIREFOX_PREF_PREFIX,
+      FIREFOX_BUILD_CONTENT_DIR + 'PdfjsChromeUtils.jsm');
 
   // Update localized metadata
   var localizedMetadata = cat(EXTENSION_SRC_DIR + '/firefox/metadata.inc');
@@ -808,6 +810,8 @@ target.mozcentral = function() {
       MOZCENTRAL_CONTENT_DIR + 'PdfStreamConverter.jsm');
   sed('-i', /PDFJSSCRIPT_MOZ_CENTRAL/, 'true',
       MOZCENTRAL_CONTENT_DIR + 'PdfStreamConverter.jsm');
+  sed('-i', /PDFJSSCRIPT_PREF_PREFIX/, MOZCENTRAL_PREF_PREFIX,
+      MOZCENTRAL_CONTENT_DIR + 'PdfjsChromeUtils.jsm');
 
   // Copy test files
   mkdir('-p', MOZCENTRAL_TEST_DIR);