diff --git a/build123d/default.nix b/build123d/default.nix
index 035045f..8050c65 100644
--- a/build123d/default.nix
+++ b/build123d/default.nix
@@ -20,7 +20,6 @@
         lib,
         config,
         pkgs,
-        self',
         system,
         ...
       }: let