diff --git a/tests/unit/managers/test_opc_manager.py b/tests/unit/managers/test_opc_manager.py
index 4162c28..7f022b7 100644
--- a/tests/unit/managers/test_opc_manager.py
+++ b/tests/unit/managers/test_opc_manager.py
@@ -44,7 +44,8 @@ metadata = {
 
 
 @fixture
-def raw_opc_manager():
+@patch("ingestor.managers.opc_manager.metrics")
+def raw_opc_manager(mock_metrics):
     return OpcManager(
         name="TestConnector",
         url="opc.tcp://localhost:4840",