diff --git a/extensions/firefox/components/PdfStreamConverter.js b/extensions/firefox/components/PdfStreamConverter.js
index 4467abc6b..f4b5b7712 100644
--- a/extensions/firefox/components/PdfStreamConverter.js
+++ b/extensions/firefox/components/PdfStreamConverter.js
@@ -153,7 +153,7 @@ PdfStreamConverter.prototype = {
                     'resource://pdf.js/web/viewer.html', null, null);
 
     var listener = this.listener;
-    // Proxy all the requst observer calls, when it gets to onStopRequst
+    // Proxy all the request observer calls, when it gets to onStopRequest
     // we can get the dom window.
     var proxy = {
       onStartRequest: function() {