diff --git a/devShell.nix b/devShell.nix
index d3fcd9dd6..117b4fcc6 100644
--- a/devShell.nix
+++ b/devShell.nix
@@ -44,6 +44,9 @@
           # vendoring / needed for impure tests
           ln -sfT ${self'.packages.clan-cli.nixpkgs} "$PRJ_ROOT/pkgs/clan-cli/clan_lib/nixpkgs"
           ln -sfT ${inputs.nix-select} "$PRJ_ROOT/pkgs/clan-cli/clan_lib/select"
+
+          # Generate classes.py from schemas
+          ${self'.packages.classgen}/bin/classgen ${self'.legacyPackages.schemas.clan-schema-abstract}/schema.json $PRJ_ROOT/pkgs/clan-cli/clan_lib/nix_models/clan.py
         '';
       };
     };
diff --git a/pkgs/clan-cli/shell.nix b/pkgs/clan-cli/shell.nix
index 74cab1fce..55932e004 100644
--- a/pkgs/clan-cli/shell.nix
+++ b/pkgs/clan-cli/shell.nix
@@ -45,8 +45,5 @@ mkShell {
 
     # Add clan command to PATH
     export PATH="$PKG_ROOT/bin":"$PATH"
-
-    # Generate classes.py from schemas
-    ${self'.packages.classgen}/bin/classgen ${self'.legacyPackages.schemas.clan-schema-abstract}/schema.json $PKG_ROOT/clan_lib/nix_models/clan.py
   '';
 }