diff --git a/custom_components/xiaomi_home/miot/miot_spec.py b/custom_components/xiaomi_home/miot/miot_spec.py
index 7ee69a7..1980cc4 100644
--- a/custom_components/xiaomi_home/miot/miot_spec.py
+++ b/custom_components/xiaomi_home/miot/miot_spec.py
@@ -784,8 +784,11 @@ class MIoTSpecParser:
         _LOGGER.debug('parse urn, %s', urn)
         # Load spec instance
         instance: dict = await self.__get_instance(urn=urn)
+        urn_strs: list[str] = urn.split(':')
+        urn_key: str = ':'.join(urn_strs[:6])
         # Modify the spec instance by custom spec
-        instance = self._custom_service.modify_spec(urn=urn, spec=instance)
+        instance = self._custom_service.modify_spec(urn_key=urn_key, spec=instance)
+        # Check required fields in the device instance
         if (
             not isinstance(instance, dict)
             or 'type' not in instance
@@ -803,8 +806,6 @@ class MIoTSpecParser:
                 or not isinstance(res_trans['data'], dict)
             ):
                 raise MIoTSpecError('invalid translation data')
-            urn_strs: list[str] = urn.split(':')
-            urn_key: str = ':'.join(urn_strs[:6])
             trans_data: dict[str, str] = None
             if self._lang == 'zh-Hans':
                 # Simplified Chinese
diff --git a/custom_components/xiaomi_home/miot/miot_storage.py b/custom_components/xiaomi_home/miot/miot_storage.py
index 099b6db..dbbc734 100644
--- a/custom_components/xiaomi_home/miot/miot_storage.py
+++ b/custom_components/xiaomi_home/miot/miot_storage.py
@@ -1071,17 +1071,17 @@ class SpecCustomService:
     async def deinit_async(self) -> None:
         self._data = None
 
-    def modify_spec(self, urn: str, spec: dict) -> dict | None:
+    def modify_spec(self, urn_key: str, spec: dict) -> dict | None:
         """MUST call init_async() first."""
         if not self._data:
             _LOGGER.error('self._data is None')
             return spec
-        if urn not in self._data:
+        if urn_key not in self._data:
             return spec
         if 'services' not in spec:
             return spec
         spec_services = spec['services']
-        custom_spec = self._data.get(urn, None)
+        custom_spec = self._data.get(urn_key, None)
         # Replace services by custom defined spec
         for i, service in enumerate(spec_services):
             siid = str(service['iid'])
diff --git a/custom_components/xiaomi_home/miot/specs/custom_service.json b/custom_components/xiaomi_home/miot/specs/custom_service.json
index 1bc4bc6..70cc46c 100644
--- a/custom_components/xiaomi_home/miot/specs/custom_service.json
+++ b/custom_components/xiaomi_home/miot/specs/custom_service.json
@@ -1,5 +1,5 @@
 {
-    "urn:miot-spec-v2:device:airer:0000A00D:hyd-lyjpro:1": {
+    "urn:miot-spec-v2:device:airer:0000A00D:hyd-lyjpro": {
         "3": {
             "iid": 3,
             "type": "urn:miot-spec-v2:service:light:00007802:hyd-lyjpro:1",
diff --git a/custom_components/xiaomi_home/miot/specs/multi_lang.json b/custom_components/xiaomi_home/miot/specs/multi_lang.json
index 5e48bcc..7f16732 100644
--- a/custom_components/xiaomi_home/miot/specs/multi_lang.json
+++ b/custom_components/xiaomi_home/miot/specs/multi_lang.json
@@ -155,7 +155,7 @@
             "service:004:property:001": "事件名稱"
         }
     },
-    "urn:miot-spec-v2:device:switch:0000A003:lumi-acn040:1": {
+    "urn:miot-spec-v2:device:switch:0000A003:lumi-acn040": {
         "en": {
             "service:011": "Right Button On and Off",
             "service:011:property:001": "Right Button On and Off",