diff --git a/tests/test_four_phase_unit.py b/tests/test_four_phase_unit.py
index e142e01..2462071 100644
--- a/tests/test_four_phase_unit.py
+++ b/tests/test_four_phase_unit.py
@@ -201,6 +201,7 @@ class TestU3RoundComplete:
         from src.blackboard.db import get_connection
         conn = get_connection(db_path)
         conn.execute("UPDATE tasks SET status='done' WHERE id='parent'")
+        conn.commit()
         conn.close()
 
         # mock spawner
@@ -265,6 +266,7 @@ class TestU4RoundWithFailed:
         from src.blackboard.db import get_connection
         conn = get_connection(db_path)
         conn.execute("UPDATE tasks SET status='done' WHERE id='parent'")
+        conn.commit()
         conn.close()
 
         mock_spawner = MagicMock()
@@ -298,6 +300,7 @@ class TestU5RoundLimit:
         from src.blackboard.db import get_connection
         conn = get_connection(db_path)
         conn.execute("UPDATE tasks SET status='done', round_count=5 WHERE id='parent'")
+        conn.commit()
         conn.close()
 
         ticker = Ticker(registry=MagicMock(), spawner=MagicMock(),
@@ -319,6 +322,7 @@ class TestU5RoundLimit:
         from src.blackboard.db import get_connection
         conn = get_connection(db_path)
         conn.execute("UPDATE tasks SET status='done', round_count=4 WHERE id='parent'")
+        conn.commit()
         conn.close()
 
         mock_spawner = MagicMock()