diff --git a/tests/test_warmtelink_worker.py b/tests/test_warmtelink_worker.py
index 296918e..cef860a 100644
--- a/tests/test_warmtelink_worker.py
+++ b/tests/test_warmtelink_worker.py
@@ -261,6 +261,8 @@ def test_lifespan_exception_still_shuts_serial_before_other_runtime_teardown(mon
     import app.main as main
 
     events = []
+    runtime_settings = object()
+    applied_dsmr_settings = []
 
     class _Scheduler:
         def __init__(self, **_kwargs): pass
@@ -279,8 +281,13 @@ def test_lifespan_exception_still_shuts_serial_before_other_runtime_teardown(mon
     monkeypatch.setattr(main, "ensure_auth_db_ready", lambda: None)
     monkeypatch.setattr(main, "BackgroundScheduler", _Scheduler)
     monkeypatch.setattr(main, "get_session_local", lambda: _Session)
-    monkeypatch.setattr(main, "build_runtime_settings", lambda *_args: object())
-    monkeypatch.setattr(main, "apply_dsmr_subscription", lambda: None)
+    monkeypatch.setattr(main, "build_runtime_settings", lambda *_args: runtime_settings)
+
+    def apply_dsmr_subscription(settings=runtime_settings):
+        assert settings is runtime_settings
+        applied_dsmr_settings.append(settings)
+
+    monkeypatch.setattr(main, "apply_dsmr_subscription", apply_dsmr_subscription)
     monkeypatch.setattr(main.mqtt_manager, "connect", lambda _settings: events.append("mqtt-start"))
     monkeypatch.setattr(main.mqtt_manager, "disconnect", lambda: events.append("mqtt-stop"))
     monkeypatch.setattr(main, "warmtelink_worker_manager", _Manager())
@@ -293,6 +300,7 @@ def test_lifespan_exception_still_shuts_serial_before_other_runtime_teardown(mon
             pass
 
     anyio.run(exercise)
+    assert applied_dsmr_settings == [runtime_settings]
     assert events.index("serial-stop-close-join") < events.index("mqtt-stop") < events.index("scheduler-stop")