diff --git a/nix/testenv.nix b/nix/testenv.nix
index 5a0292ff8f..f0f20edd5a 100644
--- a/nix/testenv.nix
+++ b/nix/testenv.nix
@@ -23,7 +23,7 @@ poetry2nix.mkPoetryEnv {
     lib.mapAttrs
       (attr: systems: super.${attr}.overridePythonAttrs
         (old: {
-          nativeBuildInputs = (old.nativeBuildInputs or [ ]) ++ map (a: self.${a}) systems;
+          nativeBuildInputs = (old.nativeBuildInputs or [ ]) ++ [ self.clang ] ++ map (a: self.${a}) systems;
         }))
       buildSystems
   );