diff --git a/pkgs/development/compilers/ghc/head.nix b/pkgs/development/compilers/ghc/head.nix
index 035ebc8b268..1ea283f87fe 100644
--- a/pkgs/development/compilers/ghc/head.nix
+++ b/pkgs/development/compilers/ghc/head.nix
@@ -1,12 +1,12 @@
 { stdenv, fetchurl, ghc, perl, gmp, ncurses }:
 
 stdenv.mkDerivation rec {
-  version = "7.7";
+  version = "7.7.20130811";
   name = "ghc-${version}";
 
   src = fetchurl {
-    url = "http://haskell.org/ghc/dist/current/dist/${name}-src.tar.bz2";
-    sha256 = "1f4grj1lw25vb5drn4sn8fc1as3hwhk8dl659spi5fnbrs5k4wgb";
+    url = "http://darcs.haskell.org/ghcBuilder/uploads/tn23/${name}-src.tar.bz2";
+    sha256 = "1jkks2nq9189vxim9lfiwmf3wrnxi834brv9kn9n31225f34qdyr";
   };
 
   buildInputs = [ ghc perl gmp ncurses ];
@@ -19,24 +19,16 @@ stdenv.mkDerivation rec {
     DYNAMIC_BY_DEFAULT = NO
   '';
 
-  # The tarball errorneously contains an executable that doesn't work in
-  # Nix. Deleting it will cause the program to be re-built locally.
-  postUnpack = ''
-    rm -v $sourceRoot/libraries/integer-gmp/cbits/mkGmpDerivedConstants
-  '';
-
   preConfigure = ''
     echo "${buildMK}" > mk/build.mk
     sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
   '';
 
-  configureFlags=[
-    "--with-gcc=${stdenv.gcc}/bin/gcc"
-  ];
+  configureFlags = "--with-gcc=${stdenv.gcc}/bin/gcc";
 
   # required, because otherwise all symbols from HSffi.o are stripped, and
   # that in turn causes GHCi to abort
-  stripDebugFlags=["-S" "--keep-file-symbols"];
+  stripDebugFlags = [ "-S" "--keep-file-symbols" ];
 
   meta = {
     homepage = "http://haskell.org/ghc";