diff --git a/pkgs/applications/networking/browsers/firefox/9.0.nix b/pkgs/applications/networking/browsers/firefox/12.0.nix
similarity index 94%
rename from pkgs/applications/networking/browsers/firefox/9.0.nix
rename to pkgs/applications/networking/browsers/firefox/12.0.nix
index 327f454f5781..d4b90d2726f1 100644
--- a/pkgs/applications/networking/browsers/firefox/9.0.nix
+++ b/pkgs/applications/networking/browsers/firefox/12.0.nix
@@ -15,14 +15,14 @@ assert stdenv.gcc ? libc && stdenv.gcc.libc != null;
 
 rec {
 
-  firefoxVersion = "9.0.1";
+  firefoxVersion = "12.0";
   
-  xulVersion = "9.0.1"; # this attribute is used by other packages
+  xulVersion = "12.0"; # 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 = "e0748d86753eead5c0929d74158c601bf33b5db0";
+    sha1 = "0177185e54b7d63dc36bd5bd5c80ba6afd52e199";
   };
   
   commonConfigureFlags =
@@ -35,7 +35,7 @@ rec {
       "--with-system-nspr"
       # "--with-system-nss"
       # "--with-system-png" # <-- "--with-system-png won't work because the system's libpng doesn't have APNG support"
-      "--enable-system-cairo"
+      # "--enable-system-cairo" # disabled for the moment because our Cairo is too old
       "--enable-system-sqlite"
       "--disable-crashreporter"
       "--disable-tests"
@@ -139,7 +139,7 @@ rec {
       [ "--enable-application=browser"
         "--with-libxul-sdk=${xulrunner}/lib/xulrunner-devel-${xulrunner.version}"
         "--enable-chrome-format=jar"
-	"--disable-elf-hack"
+        "--disable-elf-hack"
       ]
       ++ commonConfigureFlags
       ++ stdenv.lib.optional enableOfficialBranding "--enable-official-branding";
@@ -170,6 +170,7 @@ rec {
     meta = {
       description = "Mozilla Firefox - the browser, reloaded";
       homepage = http://www.mozilla.com/en-US/firefox/;
+      maintainers = [ stdenv.lib.maintainers.eelco ];
     };
 
     passthru = {
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index f52711eaf532..76302a63b8ec 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -6752,12 +6752,6 @@ let
 
   firefox36Wrapper = wrapFirefox { browser = firefox36Pkgs.firefox; };
 
-  firefox9Pkgs = callPackage ../applications/networking/browsers/firefox/9.0.nix {
-    inherit (gnome) libIDL;
-  };
-
-  firefox9Wrapper = wrapFirefox { browser = firefox9Pkgs.firefox; };
-
   firefox10Pkgs = callPackage ../applications/networking/browsers/firefox/10.0.nix {
     inherit (gnome) libIDL;
   };
@@ -6770,6 +6764,12 @@ let
 
   firefox11Wrapper = wrapFirefox { browser = firefox11Pkgs.firefox; };
 
+  firefox12Pkgs = callPackage ../applications/networking/browsers/firefox/12.0.nix {
+    inherit (gnome) libIDL;
+  };
+
+  firefox12Wrapper = wrapFirefox { browser = firefox12Pkgs.firefox; };
+
   flac = callPackage ../applications/audio/flac { };
 
   flashplayer = flashplayer11;
diff --git a/pkgs/top-level/release.nix b/pkgs/top-level/release.nix
index 1d2551352b8f..67aec37a821b 100644
--- a/pkgs/top-level/release.nix
+++ b/pkgs/top-level/release.nix
@@ -362,6 +362,7 @@ with (import ./release-lib.nix);
   firefox36Pkgs.firefox = linux;
   firefox10Pkgs.firefox = linux;
   firefox11Pkgs.firefox = linux;
+  firefox12Pkgs.firefox = linux;
 
   gnome = {
     gnome_panel = linux;