diff --git a/custom_components/sigmesh_gateway/coordinator.py b/custom_components/sigmesh_gateway/coordinator.py
index 9f3c50b..778ecc2 100644
--- a/custom_components/sigmesh_gateway/coordinator.py
+++ b/custom_components/sigmesh_gateway/coordinator.py
@@ -14,12 +14,14 @@ from .const import DOMAIN
 from .protocol_parser import (
     DeviceManager,
     DeviceState,
-    MeshMessageEvent,
     ParsedMeshMessage,
-    ProvDeviceEvent,
     ProtocolParser,
 )
-from .serial_reader import SerialReader
+from .serial_reader import (
+    MeshMessageEvent,
+    ProvDeviceEvent,
+    SerialReader,
+)
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -57,12 +59,6 @@ class SigMeshGatewayCoordinator(DataUpdateCoordinator[dict[str, DeviceState]]):
 
     def _setup_callbacks(self) -> None:
         """设置串口读取器的回调函数."""
-        from .serial_reader import (
-            MeshMessageEvent,
-            ProvDeviceEvent,
-            SerialDataEvent,
-        )
-
         def on_mesh_message_handler(event: MeshMessageEvent) -> None:
             """处理 Mesh 消息回调."""
             self.hass.async_create_task(self._handle_mesh_message(event))