diff --git a/pkgs/development/compilers/ghc/boot.nix b/pkgs/development/compilers/ghc/boot.nix
index c1297ca814f..52c8374f4ac 100644
--- a/pkgs/development/compilers/ghc/boot.nix
+++ b/pkgs/development/compilers/ghc/boot.nix
@@ -1,15 +1,20 @@
-{stdenv, fetchurl, perl, readline, ncurses}:
+{stdenv, fetchurl, perl, readline, ncurses, gmp ? null}:
 
-assert stdenv.system == "i686-linux";
+assert stdenv.system == "i686-linux" || stdenv.system == "x86_64-linux";
 
 stdenv.mkDerivation {
   name = "ghc-6.4.2";
   builder = ./boot.sh;
-  src = fetchurl {
-    url = http://nix.cs.uu.nl/dist/tarballs/ghc-6.4.2-i386-unknown-linux.tar.bz2;
-    md5 = "092fe2e25dab22b926babe97cc77db1f";
-  };
+  src = if stdenv.system == "i686-linux" then
+        (fetchurl {
+             url = http://nix.cs.uu.nl/dist/tarballs/ghc-6.4.2-i386-unknown-linux.tar.bz2;
+             md5 = "092fe2e25dab22b926babe97cc77db1f";
+        }) else
+        (fetchurl {
+             url = http://haskell.org/ghc/dist/6.4.2/ghc-6.4.2-x86_64-unknown-linux.tar.bz2;
+             md5 = "8f5fe48798f715cd05214a10987bf6d5";
+        });             
   buildInputs = [perl];
-  propagatedBuildInputs = [readline ncurses];
-  inherit readline ncurses;
+  propagatedBuildInputs = [readline ncurses (if stdenv.system == "x86_64-linux" then gmp else null)];
+  inherit readline ncurses gmp;
 }
diff --git a/pkgs/development/compilers/ghc/boot.sh b/pkgs/development/compilers/ghc/boot.sh
index e952f5d17ab..4b88b6bdba3 100644
--- a/pkgs/development/compilers/ghc/boot.sh
+++ b/pkgs/development/compilers/ghc/boot.sh
@@ -4,7 +4,7 @@ postBuild=postBuild
 postBuild () {
     find . -type f -perm +100 \
         -exec patchelf --interpreter "$(cat $NIX_GCC/nix-support/dynamic-linker)" \
-        --set-rpath "$readline/lib:$ncurses/lib" {} \;
+        --set-rpath "$readline/lib:$ncurses/lib:$gmp/lib" {} \;
 }
 
 genericBuild
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 832f7d39902..24f1135b167 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -770,7 +770,8 @@ rec {
 
   ghcboot = lowPrio (appendToName "boot" (import ../development/compilers/ghc/boot.nix {
     inherit fetchurl stdenv perl ncurses;
-    readline = readline4;
+    readline = if stdenv.system == "i686-linux" then readline4 else readline;
+    gmp = if stdenv.system == "x86_64-linux" then gmp else null;
   }));
 
   /*