diff --git a/extensions/firefox/components/PdfStreamConverter.js b/extensions/firefox/components/PdfStreamConverter.js
index 641ceb486..cede62d57 100644
--- a/extensions/firefox/components/PdfStreamConverter.js
+++ b/extensions/firefox/components/PdfStreamConverter.js
@@ -31,8 +31,6 @@ const PREF_PREFIX = 'PDFJSSCRIPT_PREF_PREFIX';
 const PDF_VIEWER_WEB_PAGE = 'resource://pdf.js/web/viewer.html';
 const MAX_DATABASE_LENGTH = 4096;
 const FIREFOX_ID = '{ec8030f7-c20a-464f-9b0e-13a3a9e97384}';
-const SEAMONKEY_ID = '{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}';
-const METRO_ID = '{99bceaaa-e3c6-48c1-b981-ef9b46b67d60}';
 
 Cu.import('resource://gre/modules/XPCOMUtils.jsm');
 Cu.import('resource://gre/modules/Services.jsm');