diff --git a/tests/conftest.py b/tests/conftest.py
index ccd247a..1140f21 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -65,6 +65,7 @@ sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")
 # precisely because PyGObject was installed and already loaded.
 _mock_gi = MagicMock()
 _mock_gi_repository = MagicMock()
+_mock_gi_repository.Notify = MagicMock()
 sys.modules["gi"] = _mock_gi
 sys.modules["gi.repository"] = _mock_gi_repository
 
diff --git a/tests/test_main_args_deps.py b/tests/test_main_args_deps.py
index 4a500ca..e2d67a7 100644
--- a/tests/test_main_args_deps.py
+++ b/tests/test_main_args_deps.py
@@ -274,12 +274,10 @@ class TestMainFunction(unittest.TestCase):
         """Test main() when another instance is already running."""
         from vocalinux.main import main
 
-        # Mock single_instance module since it's imported inside main()
         mock_single_instance = MagicMock()
         mock_single_instance.acquire_lock.return_value = False
 
         with patch.dict(sys.modules, {"vocalinux.single_instance": mock_single_instance}):
-            # Should exit with status 1
             with pytest.raises(SystemExit) as exc_info:
                 main()
             assert exc_info.value.code == 1