diff --git a/pkgs/development/compilers/llvm/common/clang/default.nix b/pkgs/development/compilers/llvm/common/clang/default.nix
index c5565ca405b8..d35328a9e62d 100644
--- a/pkgs/development/compilers/llvm/common/clang/default.nix
+++ b/pkgs/development/compilers/llvm/common/clang/default.nix
@@ -298,6 +298,7 @@ stdenv.mkDerivation (
         ++ (finalAttrs.passthru.hardeningUnsupportedFlags or [ ]);
     };
 
+    requiredSystemFeatures = [ "big-parallel" ];
     meta = llvm_meta // {
       homepage = "https://clang.llvm.org/";
       description = "C language family frontend for LLVM";
diff --git a/pkgs/development/compilers/llvm/common/mlir/default.nix b/pkgs/development/compilers/llvm/common/mlir/default.nix
index 40733ac29bb5..d3d4a03ba7a7 100644
--- a/pkgs/development/compilers/llvm/common/mlir/default.nix
+++ b/pkgs/development/compilers/llvm/common/mlir/default.nix
@@ -87,6 +87,7 @@ stdenv.mkDerivation (finalAttrs: {
     "dev"
   ];
 
+  requiredSystemFeatures = [ "big-parallel" ];
   meta = llvm_meta // {
     # Very broken since the dependencies aren't propagating at all with tblgen through the CMake.
     broken = lib.versionAtLeast release_version "20";