diff --git a/tests/unit/test_app.py b/tests/unit/test_app.py
index dda7701..5705c67 100644
--- a/tests/unit/test_app.py
+++ b/tests/unit/test_app.py
@@ -128,7 +128,7 @@ def test_main_successful_run_one_loop(mock_app_env, capsys):
     mock_ingestor_instance.logger.info.assert_any_call("Main loop exit_signaled.")
 
     captured = capsys.readouterr()
-    assert "Prometheus server started on port 8000." in captured.out
+    assert "Prometheus server started on port 4840." in captured.out
 
 
 def test_main_prometheus_server_fails_to_start(mock_app_env, capsys):