diff --git a/package/x11/firefox/firefox.conf b/package/x11/firefox/firefox.conf
index 12675f2b5..5c12e3c84 100644
--- a/package/x11/firefox/firefox.conf
+++ b/package/x11/firefox/firefox.conf
@@ -40,6 +40,7 @@ moz_main() {
 	# we must not have $ver defined on the firefox version.
 	# it would become the "rv-part" of the User-Agent ID-String.
 	# we need to set it to the milestone version (mozilla version)
+	old_ver="$ver"
 	export ver="`grep '^[0-9]' ./config/milestone.txt`"
 	moz_fixup
 	moz_implant_version
@@ -69,5 +70,7 @@ EOT
 	moz_register
 	# this annoying javascript (tm) based whatever component registration
 	$root/$bindir/firefox -register
+
+	ver="$old_ver"
 }