diff --git a/tests/test_four_phase_unit.py b/tests/test_four_phase_unit.py
index 5f8af45..9170755 100644
--- a/tests/test_four_phase_unit.py
+++ b/tests/test_four_phase_unit.py
@@ -339,6 +339,7 @@ class TestU5RoundLimit:
         ticker = Ticker(registry=MagicMock(), spawner=mock_spawner,
                         dispatcher=MagicMock())
 
+        ticker._build_review_prompt = MagicMock(return_value="Review prompt mock")
         async def run():
             return await ticker._check_round_complete(db_path, pid)