diff --git a/pkgs/stdenv/darwin/default.nix b/pkgs/stdenv/darwin/default.nix
index 26114d2726e1..cbc9a38b77de 100644
--- a/pkgs/stdenv/darwin/default.nix
+++ b/pkgs/stdenv/darwin/default.nix
@@ -1,6 +1,6 @@
 { stdenv, pkgs, config
 , haveLibCxx ? true
-, useClang33 ? false }:
+, useClang33 ? true }:
 
 import ../generic rec {
   inherit config;
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index cf5099b3673a..229c59f3b6ee 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -11856,7 +11856,6 @@ let
   };
 
   nixUnstable = callPackage ../tools/package-management/nix/unstable.nix {
-    stdenv = if stdenv.isDarwin then allStdenvs.stdenvDarwin33 else stdenv;
     storeDir = config.nix.storeDir or "/nix/store";
     stateDir = config.nix.stateDir or "/nix/var";
   };