GeezerVison

diff --git a/test/test_index.py b/test/test_index.py
index 233a4c64..d6373250 100644
--- a/test/test_index.py
+++ b/test/test_index.py
@@ -56,14 +56,14 @@ HOOKS_SHEBANG = "#!/usr/bin/env sh\n"
 is_win_without_bash = is_win and not shutil.which('bash.exe')
 
 
-def _make_hook(git_dir, name, content, make_exec=True):
+def _make_hook(git_dir, name, content, make_exec=True, shebang=HOOKS_SHEBANG):
     """A helper to create a hook"""
     hp = hook_path(name, git_dir)
     hpd = osp.dirname(hp)
     if not osp.isdir(hpd):
         os.mkdir(hpd)
     with open(hp, "wt") as fp:
-        fp.write(HOOKS_SHEBANG + content)
+        fp.write(shebang + content)
     if make_exec:
         os.chmod(hp, 0o744)
     return hp
@@ -912,6 +912,33 @@ class TestIndex(TestBase):
         new_commit = index.commit(commit_message)
         self.assertEqual(new_commit.message, "{} {}".format(commit_message, from_hook_message))
 
+    @with_rw_repo('HEAD', bare=True)
+    def test_commit_msg_hook_success_in_py(self, rw_repo):
+        index = rw_repo.index
+        hp = _make_hook(
+            index.repo.git_dir,
+            'commit-msg',
+            "import sys; print('stdout'); print('stderr', file=sys.stderr); sys.exit(1)",
+            shebang = "#!/usr/bin/env python3\n"
+        )
+        try:
+            index.commit("This should fail")
+        except HookExecutionError as err:
+            if is_win_without_bash:
+                self.assertIsInstance(err.status, OSError)
+                self.assertEqual(err.command, [hp])
+                self.assertEqual(err.stdout, '')
+                self.assertEqual(err.stderr, '')
+                assert str(err)
+            else:
+                self.assertEqual(err.status, 1)
+                self.assertEqual(err.command, [hp])
+                self.assertEqual(err.stdout, "\n  stdout: 'stdout\n'")
+                self.assertEqual(err.stderr, "\n  stderr: 'stderr\n'")
+                assert str(err)
+        else:
+            raise AssertionError("Should have cought a HookExecutionError")
+
     @with_rw_repo('HEAD', bare=True)
     def test_commit_msg_hook_fail(self, rw_repo):
         index = rw_repo.index

#! /bin/sh
$1

        cmd = ["bash.exe", "call_from_unix.sh", relative_hp]