diff --git a/api/src/dooris_api/ccujack.py b/api/src/dooris_api/ccujack.py
index 8cf767f..6856128 100644
--- a/api/src/dooris_api/ccujack.py
+++ b/api/src/dooris_api/ccujack.py
@@ -83,7 +83,7 @@ class CCUJackClient:
             connector=TCPConnector(ssl=False),
         )
         self.mqtt = AsyncMqttClient(mqtt_conn, auth.login, auth.password)
-        self.locks = None
+        self.locks = []
         self.param_values = dict()
         self.task_process_messages = None
         self.task_find_locks = None