diff --git a/shell.nix b/shell.nix
index c19ac4d..8fdc1a2 100644
--- a/shell.nix
+++ b/shell.nix
@@ -3,8 +3,9 @@
 pkgs.mkShell {
   name = "hb-downloader";
   buildInputs = [
-    (pkgs.python3.withPackages ( pyPkgs: [
-        pyPkgs.requests
+    (pkgs.python3.withPackages ( pyPkgs: with pyPkgs; [
+        requests
+        mypy
     ]))
   ];
   nativeBuildInputs = [