diff --git a/pkgs/development/python-modules/pygobject/default.nix b/pkgs/development/python-modules/pygobject/default.nix
index 5c9367a1f460..7f2bd63dc24d 100644
--- a/pkgs/development/python-modules/pygobject/default.nix
+++ b/pkgs/development/python-modules/pygobject/default.nix
@@ -26,6 +26,10 @@ mkPythonDerivation rec {
   # effect, but we leave it in case somebody expects and calls it.
   postInstall = ''
     mv $out/lib/${python.libPrefix}/site-packages/{pygtk.pth,${name}.pth}
+
+    # Prevent wrapping of codegen files as these are meant to be
+    # executed by the python program
+    chmod a-x $out/share/pygobject/*/codegen/*.py
   '';
 
   meta = {