diff --git a/tests/test_redis_lock.py b/tests/test_redis_lock.py
index ac9e3ef..331ab41 100644
--- a/tests/test_redis_lock.py
+++ b/tests/test_redis_lock.py
@@ -552,7 +552,7 @@ def test_signal_expiration(conn, signal_expire, method):
         lock.release()
     elif method == 'reset_all':
         reset_all(conn)
-    time.sleep(0.5)
+    time.sleep(0.6)
     assert conn.exists('lock-signal:signal_expiration')
     time.sleep((signal_expire - 500) / 1000.0)
     assert conn.llen('lock-signal:signal_expiration') == 0