diff --git a/custom_components/xiaomi_home/miot/miot_device.py b/custom_components/xiaomi_home/miot/miot_device.py
index 353b28f..17bf9da 100644
--- a/custom_components/xiaomi_home/miot/miot_device.py
+++ b/custom_components/xiaomi_home/miot/miot_device.py
@@ -142,7 +142,7 @@ class MIoTDevice:
     _room_id: str
     _room_name: str
 
-    _suggested_area: str
+    _suggested_area: Optional[str]
 
     _device_state_sub_list: dict[str, Callable[[str, MIoTDeviceState], None]]
 
@@ -153,7 +153,7 @@ class MIoTDevice:
 
     def __init__(
         self, miot_client: MIoTClient,
-        device_info: dict[str, str],
+        device_info: dict[str, Any],
         spec_instance: MIoTSpecInstance
     ) -> None:
         self.miot_client = miot_client
@@ -243,25 +243,29 @@ class MIoTDevice:
         return True
 
     def sub_property(
-        self, handler: Callable[[dict, Any], None], siid: int = None,
-        piid: int = None, handler_ctx: Any = None
+        self, handler: Callable[[dict, Any], None], siid: Optional[int] = None,
+        piid: Optional[int] = None, handler_ctx: Any = None
     ) -> bool:
         return self.miot_client.sub_prop(
             did=self._did, handler=handler, siid=siid, piid=piid,
             handler_ctx=handler_ctx)
 
-    def unsub_property(self, siid: int = None, piid: int = None) -> bool:
+    def unsub_property(
+        self, siid: Optional[int] = None, piid: Optional[int] = None
+    ) -> bool:
         return self.miot_client.unsub_prop(did=self._did, siid=siid, piid=piid)
 
     def sub_event(
-        self, handler: Callable[[dict, Any], None], siid: int = None,
-        eiid: int = None, handler_ctx: Any = None
+        self, handler: Callable[[dict, Any], None], siid: Optional[int] = None,
+        eiid: Optional[int] = None, handler_ctx: Any = None
     ) -> bool:
         return self.miot_client.sub_event(
             did=self._did, handler=handler, siid=siid, eiid=eiid,
             handler_ctx=handler_ctx)
 
-    def unsub_event(self, siid: int = None, eiid: int = None) -> bool:
+    def unsub_event(
+        self, siid: Optional[int] = None, eiid: Optional[int] = None
+    ) -> bool:
         return self.miot_client.unsub_event(
             did=self._did, siid=siid, eiid=eiid)
 
@@ -703,7 +707,7 @@ class MIoTDevice:
     def __on_device_state_changed(
         self, did: str, state: MIoTDeviceState, ctx: Any
     ) -> None:
-        self._online = state
+        self._online = state == MIoTDeviceState.ONLINE
         for key, handler in self._device_state_sub_list.items():
             self.miot_client.main_loop.call_soon_threadsafe(
                 handler, key, state)
@@ -719,7 +723,8 @@ class MIoTServiceEntity(Entity):
     _main_loop: asyncio.AbstractEventLoop
     _prop_value_map: dict[MIoTSpecProperty, Any]
 
-    _event_occurred_handler: Callable[[MIoTSpecEvent, dict], None]
+    _event_occurred_handler: Optional[
+        Callable[[MIoTSpecEvent, dict], None]]
     _prop_changed_subs: dict[
         MIoTSpecProperty, Callable[[MIoTSpecProperty, Any], None]]
 
@@ -763,7 +768,9 @@ class MIoTServiceEntity(Entity):
             self.entity_id)
 
     @property
-    def event_occurred_handler(self) -> Callable[[MIoTSpecEvent, dict], None]:
+    def event_occurred_handler(
+        self
+    ) -> Optional[Callable[[MIoTSpecEvent, dict], None]]:
         return self._event_occurred_handler
 
     @event_occurred_handler.setter
@@ -784,7 +791,7 @@ class MIoTServiceEntity(Entity):
         self._prop_changed_subs.pop(prop, None)
 
     @property
-    def device_info(self) -> dict:
+    def device_info(self) -> Optional[DeviceInfo]:
         return self.miot_device.device_info
 
     async def async_added_to_hass(self) -> None:
@@ -1002,7 +1009,7 @@ class MIoTPropertyEntity(Entity):
     # {'min':int, 'max':int, 'step': int}
     _value_range: dict[str, int]
     # {Any: Any}
-    _value_list: dict[Any, Any]
+    _value_list: Optional[dict[Any, Any]]
     _value: Any
 
     _pending_write_ha_state_timer: Optional[asyncio.TimerHandle]
@@ -1042,7 +1049,7 @@ class MIoTPropertyEntity(Entity):
             self._value_list)
 
     @property
-    def device_info(self) -> dict:
+    def device_info(self) -> Optional[DeviceInfo]:
         return self.miot_device.device_info
 
     async def async_added_to_hass(self) -> None:
@@ -1067,7 +1074,7 @@ class MIoTPropertyEntity(Entity):
         self.miot_device.unsub_property(
             siid=self.service.iid, piid=self.spec.iid)
 
-    def get_vlist_description(self, value: Any) -> str:
+    def get_vlist_description(self, value: Any) -> Optional[str]:
         if not self._value_list:
             return None
         return self._value_list.get(value, None)
@@ -1184,7 +1191,7 @@ class MIoTEventEntity(Entity):
             spec.device_class, self.entity_id)
 
     @property
-    def device_info(self) -> dict:
+    def device_info(self) -> Optional[DeviceInfo]:
         return self.miot_device.device_info
 
     async def async_added_to_hass(self) -> None:
@@ -1286,7 +1293,7 @@ class MIoTActionEntity(Entity):
             spec.device_class, self.entity_id)
 
     @property
-    def device_info(self) -> dict:
+    def device_info(self) -> Optional[DeviceInfo]:
         return self.miot_device.device_info
 
     async def async_added_to_hass(self) -> None:
@@ -1298,7 +1305,9 @@ class MIoTActionEntity(Entity):
         self.miot_device.unsub_device_state(
             key=f'{self.action_platform}.{ self.service.iid}.{self.spec.iid}')
 
-    async def action_async(self, in_list: list = None) -> Optional[list]:
+    async def action_async(
+        self, in_list: Optional[list] = None
+    ) -> Optional[list]:
         try:
             return await self.miot_device.miot_client.action_async(
                 did=self.miot_device.did,