diff --git a/flake.nix b/flake.nix
index 0e0b681..3a3cdbf 100644
--- a/flake.nix
+++ b/flake.nix
@@ -38,6 +38,9 @@
             pkgs.ruff
             pythonEnv
           ];
+          shellHook = ''
+            export PYTHONPATH=${builtins.toString ./src}
+          '';
         };
       }
     ));