diff --git a/test_dbus-opendtu.py b/test_dbus-opendtu.py
new file mode 100644
index 0000000..601340b
--- /dev/null
+++ b/test_dbus-opendtu.py
@@ -0,0 +1,51 @@
+import unittest
+from unittest.mock import patch, MagicMock
+import sys
+import os
+
+# Mocking the dbus and other dependencies before importing the module to test
+sys.modules['dbus'] = MagicMock()
+sys.modules['vedbus'] = MagicMock()
+sys.modules['gi.repository'] = MagicMock()
+sys.modules['dbus.mainloop.glib'] = MagicMock()
+
+# Add the directory containing dbus_opendtu.py to the Python path
+sys.path.insert(0, os.path.abspath(os.path.dirname(__file__)))
+
+from dbus_opendtu import register_service
+
+class TestRegisterService(unittest.TestCase):
+    @patch('dbus_opendtu.config', {'DEFAULT': {'DTU': 'opendtu'}})
+    @patch('dbus_opendtu.DbusService')
+    @patch('dbus_opendtu.get_config_value')
+    @patch('dbus_opendtu.constants')
+    
+    def test_register_service(self, mock_constants, mock_get_config_value, mock_dbus_service):
+        def get_config_value_side_effect(key, *args, **kwargs):
+            if isinstance(key, dict):
+                key = key.get('key', 'mock_value')
+            return {
+                'number_of_inverters': 2,
+                'number_of_templates': 1,
+                'DTU': 'openDTU'
+            }.get(key, 'mock_value')
+
+        mock_get_config_value.side_effect = get_config_value_side_effect
+        #mock_dbus_service.return_value = MagicMock()
+        mock_dbus_service_instance = mock_dbus_service.return_value
+        mock_dbus_service_instance.get_number_of_inverters.return_value = 1
+
+        register_service()
+
+        # Add assertions to verify the behavior
+        mock_dbus_service.assert_called_once()
+
+        # Additional assertions
+        mock_dbus_service.assert_called_once_with(
+            servicename="mock_value",
+            paths=unittest.mock.ANY,
+            actual_inverter=0,
+        )
+
+if __name__ == '__main__':
+    unittest.main()
\ No newline at end of file