diff --git a/pkgs/development/compilers/llvm/3.4/llvm.nix b/pkgs/development/compilers/llvm/3.4/llvm.nix
index f7f794f4f87..d9dd1a976b3 100644
--- a/pkgs/development/compilers/llvm/3.4/llvm.nix
+++ b/pkgs/development/compilers/llvm/3.4/llvm.nix
@@ -27,7 +27,10 @@ in stdenv.mkDerivation rec {
     mv compiler-rt-* $sourceRoot/projects/compiler-rt
   '';
 
-  buildInputs = [ perl groff cmake libxml2 python libffi ] ++ stdenv.lib.optional stdenv.isLinux valgrind;
+  buildInputs =
+    [ perl groff cmake libxml2 libffi ]
+    ++ stdenv.lib.optional (!stdenv.isDarwin) python
+    ++ stdenv.lib.optional stdenv.isLinux valgrind;
 
   propagatedBuildInputs = [ ncurses zlib ];