diff --git a/pkgs/applications/networking/browsers/firefox/3.6.nix b/pkgs/applications/networking/browsers/firefox/3.6.nix
index 47754d67f3c..40b7959139d 100644
--- a/pkgs/applications/networking/browsers/firefox/3.6.nix
+++ b/pkgs/applications/networking/browsers/firefox/3.6.nix
@@ -12,14 +12,14 @@
 
 rec {
 
-  firefoxVersion = "3.6.21";
+  firefoxVersion = "3.6.27";
   
-  xulVersion = "1.9.2.21"; # this attribute is used by other packages
+  xulVersion = "1.9.2.27"; # this attribute is used by other packages
 
   
   src = fetchurl {
     url = "http://releases.mozilla.org/pub/mozilla.org/firefox/releases/${firefoxVersion}/source/firefox-${firefoxVersion}.source.tar.bz2";
-    sha1 = "3c1f001ad22d93b48e191999f548b4382db3d36c";
+    sha1 = "dd472a10e4ef5b017f00074d0325be13e832d610";
   };
 
 
@@ -50,6 +50,9 @@ rec {
       ./xulrunner-chromium-mips.patch
       ./xulrunner-mips-n32.patch
       ./xulrunner-1.9.2_beta4-mips-bus-error.patch
+
+      # Fix building on GCC 4.6.
+      ./gcc-4.6.patch
     ];
 
     buildInputs =
diff --git a/pkgs/applications/networking/browsers/firefox/gcc-4.6.patch b/pkgs/applications/networking/browsers/firefox/gcc-4.6.patch
new file mode 100644
index 00000000000..f5f685951ef
--- /dev/null
+++ b/pkgs/applications/networking/browsers/firefox/gcc-4.6.patch
@@ -0,0 +1,13 @@
+https://346825.bugs.gentoo.org/attachment.cgi?id=270163
+
+--- a/gfx/ots/src/os2.cc
++++ b/gfx/ots/src/os2.cc
+@@ -2,6 +2,8 @@
+ // Use of this source code is governed by a BSD-style license that can be
+ // found in the LICENSE file.
+ 
++#include <cstddef>
++
+ #include "os2.h"
+ 
+ #include "head.h"