diff --git a/tests/basic/test_main.py b/tests/basic/test_main.py
index 40119669e..1fe387ccf 100644
--- a/tests/basic/test_main.py
+++ b/tests/basic/test_main.py
@@ -950,7 +950,7 @@ class TestMain(TestCase):
     def test_invalid_edit_format(self):
         with GitTemporaryDirectory():
             # Suppress stderr for this test as argparse prints an error message
-            with patch("sys.stderr", new_callable=StringIO):
+            with patch("sys.stderr", new_callable=StringIO) as mock_stderr:
                 with self.assertRaises(SystemExit) as cm:
                     _ = main(
                         ["--edit-format", "not-a-real-format", "--exit", "--yes"],
@@ -959,6 +959,9 @@ class TestMain(TestCase):
                     )
                 # argparse.ArgumentParser.exit() is called with status 2 for invalid choice
                 self.assertEqual(cm.exception.code, 2)
+                stderr_output = mock_stderr.getvalue()
+                self.assertIn("invalid choice", stderr_output)
+                self.assertIn("not-a-real-format", stderr_output)
 
     def test_default_model_selection(self):
         with GitTemporaryDirectory():