diff --git a/mozilla/xulrunner/app/Makefile.in b/mozilla/xulrunner/app/Makefile.in
index d4315105f0b..eb964ec6976 100644
--- a/mozilla/xulrunner/app/Makefile.in
+++ b/mozilla/xulrunner/app/Makefile.in
@@ -50,6 +50,11 @@ DIRS		= profile
 
 PREF_JS_EXPORTS = $(srcdir)/xulrunner.js
 
+# hardcode en-US for the moment
+AB_CD = en-US
+
+DEFINES += -DAB_CD=$(AB_CD)
+
 ifeq ($(USE_SHORT_LIBNAME), 1)
 PROGRAM = xulrunner$(BIN_SUFFIX)
 else
diff --git a/mozilla/xulrunner/app/xulrunner.js b/mozilla/xulrunner/app/xulrunner.js
index c3f2b08d9e9..0d19fa42c86 100644
--- a/mozilla/xulrunner/app/xulrunner.js
+++ b/mozilla/xulrunner/app/xulrunner.js
@@ -34,6 +34,8 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+#filter substitution
+
 // We need to override the default values of these preferences since all.js
 // assumes these are in the navigator package, which for us is non-existant.
 // XXX(darin): perhaps all.js should not be seamonkey specific