diff --git a/tests/__init__.py b/tests/__init__.py
index c82bba3..c0d62af 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -28,10 +28,10 @@ class BaseWorkerTestCase(BaseTestCase):
     def setUp(self):
         super().setUp()
         self.unused_port = unused_port()
-        self.assertEqual(
-            self.run_cli(["start", "--port", self.unused_port]).exit_code, 0
-        )
+        result = self.run_cli(["start", "--port", self.unused_port])
+        self.assertEqual(result.exit_code, 0, result.stdout)
 
     def tearDown(self):
-        self.assertEqual(self.run_cli(["stop"]).exit_code, 0)
+        result = self.run_cli(["stop"])
+        self.assertEqual(result.exit_code, 0, result.stdout)
         super().tearDown()