diff --git a/pkgs/development/compilers/llvm/5/llvm.nix b/pkgs/development/compilers/llvm/5/llvm.nix
index 3abba0ed340f..c8a2433cf3db 100644
--- a/pkgs/development/compilers/llvm/5/llvm.nix
+++ b/pkgs/development/compilers/llvm/5/llvm.nix
@@ -137,6 +137,7 @@ in stdenv.mkDerivation (rec {
 
   passthru.src = src;
 
+  requiredSystemFeatures = [ "big-parallel" ];
   meta = {
     description = "Collection of modular and reusable compiler and toolchain technologies";
     homepage    = http://llvm.org/;