diff --git a/default.nix b/default.nix
index 9c7da16..510705c 100644
--- a/default.nix
+++ b/default.nix
@@ -3,7 +3,7 @@ let
 in
 
 self: super: rec {
-  python39 = super.python39.override {
+  python39 = super.pkgs.python39.override {
     packageOverrides = self: super: {
       strawberry_graphql = super.callPackage ./pkgs/strawberry_graphql {
         buildPythonPackage = super.buildPythonPackage;