diff --git a/src/utils/fonts_utils.js b/src/utils/fonts_utils.js
index bbf17a202..27bad2a58 100644
--- a/src/utils/fonts_utils.js
+++ b/src/utils/fonts_utils.js
@@ -1,5 +1,6 @@
 /* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
+/* globals CFFDictDataMap, CFFDictPrivateDataMap, CFFEncodingMap, CFFStrings, Components, Dict, dump, error, isNum, log, netscape, Stream, warn */
 /* Copyright 2012 Mozilla Foundation
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -15,6 +16,8 @@
  * limitations under the License.
  */
 
+'use strict';
+
 /*
  * The Type2 reader code below is only used for debugging purpose since Type2
  * is only a CharString format and is never used directly as a Font file.
@@ -33,7 +36,7 @@ function readCharset(aStream, aCharstrings) {
 
   var format = aStream.getByte();
   var count = aCharstrings.length - 1;
-  if (format == 0) {
+  if (format === 0) {
     charset['.notdef'] = readCharstringEncoding(aCharstrings[0]);
 
     for (var i = 1; i < count + 1; i++) {
@@ -250,7 +253,7 @@ var Type2Parser = function type2Parser(aFilePath) {
   var xhr = new XMLHttpRequest();
   xhr.open('GET', aFilePath, false);
   xhr.mozResponseType = xhr.responseType = 'arraybuffer';
-  xhr.expected = (document.URL.indexOf('file:') == 0) ? 0 : 200;
+  xhr.expected = (document.URL.indexOf('file:') === 0) ? 0 : 200;
   xhr.send(null);
   this.data = new Stream(xhr.mozResponseArrayBuffer || xhr.mozResponse ||
                          xhr.responseArrayBuffer || xhr.response);
@@ -365,7 +368,7 @@ var Type2Parser = function type2Parser(aFilePath) {
     // Read Charset
     dump('Read Charset for ' + charStrings.length + ' glyphs');
     var charsetEntry = font.get('charset');
-    if (charsetEntry == 0) {
+    if (charsetEntry === 0) {
       error('Need to support CFFISOAdobeCharset');
     } else if (charsetEntry == 1) {
       error('Need to support CFFExpert');