diff --git a/pkgs/stdenv/custom/default.nix b/pkgs/stdenv/custom/default.nix
index 4c7380118f7d..70cac774bca2 100644
--- a/pkgs/stdenv/custom/default.nix
+++ b/pkgs/stdenv/custom/default.nix
@@ -17,8 +17,8 @@ in bootStages ++ [
   (vanillaPackages: {
     inherit config overlays;
     stdenv =
-      assert vanillaPackages.hostPlatform == localSystem;
-      assert vanillaPackages.targetPlatform == localSystem;
+      assert vanillaPackages.stdenv.hostPlatform == localSystem;
+      assert vanillaPackages.stdenv.targetPlatform == localSystem;
       config.replaceStdenv { pkgs = vanillaPackages; };
   })