diff --git a/tests/components/tplink_omada/conftest.py b/tests/components/tplink_omada/conftest.py
index aef51bce87c..510a2e7a87c 100644
--- a/tests/components/tplink_omada/conftest.py
+++ b/tests/components/tplink_omada/conftest.py
@@ -129,6 +129,7 @@ def _get_mock_client(mac: str) -> OmadaNetworkClient:
             if c["wireless"]:
                 return OmadaWirelessClient(c)
             return OmadaWiredClient(c)
+    raise ValueError(f"Client with MAC {mac} not found in mock data")
 
 
 @pytest.fixture