diff --git a/pkgs/development/tools/build-managers/cmake/2.6.3.nix b/pkgs/development/tools/build-managers/cmake/2.6.3.nix
new file mode 100644
index 000000000000..bb9c3b1485f9
--- /dev/null
+++ b/pkgs/development/tools/build-managers/cmake/2.6.3.nix
@@ -0,0 +1,31 @@
+{fetchurl, stdenv, replace, ncurses}:
+
+stdenv.mkDerivation rec {
+  name = "cmake-2.6.3-RC-15";
+
+  # We look for cmake modules in .../share/cmake-${majorVersion}/Modules.
+  majorVersion = "2.6";
+
+  setupHook = ./setup-hook.sh;
+
+  meta = {
+    homepage = http://www.cmake.org/;
+    description = "Cross-Platform Makefile Generator";
+  };
+
+  src = fetchurl {
+    url = "http://www.cmake.org/files/v2.6/${name}.tar.gz";
+    sha256 = "476b6daca63c39bc46955f99f2566735d51159c43ccc716fa689ba2a2fa7e432";
+  };
+
+  postUnpack = ''
+    dontUseCmakeConfigure=1
+    source $setupHook
+    fixCmakeFiles $sourceRoot
+    echo 'SET (CMAKE_SYSTEM_PREFIX_PATH "'${ncurses}'" CACHE FILEPATH "Root for libs for cmake" FORCE)' > $sourceRoot/cmakeInit.txt
+  '';
+
+  configureFlags= [ " --init=cmakeInit.txt " ];
+
+  postInstall = "fixCmakeFiles $out/share";
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 50623a92b18c..afa6a967800c 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -2280,6 +2280,10 @@ let
     inherit fetchurl stdenv replace ncurses;
   };
 
+  cmakeUnstable = lowPrio (import ../development/tools/build-managers/cmake/2.6.3.nix {
+    inherit fetchurl stdenv replace ncurses;
+  });
+
   cproto = import ../development/tools/misc/cproto {
     inherit fetchurl stdenv flex bison;
   };