diff --git a/custom_components/xiaomi_home/miot/miot_device.py b/custom_components/xiaomi_home/miot/miot_device.py
index a08d899..994f746 100644
--- a/custom_components/xiaomi_home/miot/miot_device.py
+++ b/custom_components/xiaomi_home/miot/miot_device.py
@@ -515,20 +515,17 @@ def parse_miot_property_entity(
             prop.icon = self.icon_convert(prop.unit)
         device_class = SPEC_PROP_TRANS_MAP['properties'][prop_name][
             'device_class']
-        
         result = {'platform': platform, 'device_class': device_class}
-        
         # optional:
-        prop_optional = SPEC_PROP_TRANS_MAP['properties'][prop_name].get('optional')
-        if prop_optional:
-            prop_optional_state_class = prop_optional.get('state_class')
+        optional = SPEC_PROP_TRANS_MAP['properties'][prop_name].get('optional')
+        if optional:
+            prop_optional_state_class = optional.get('state_class')
             if prop_optional_state_class:
                 result['state_class'] = prop_optional_state_class
 
-            prop_optional_unit = prop_optional.get('unit_of_measurement')
+            prop_optional_unit = optional.get('unit_of_measurement')
             if prop_optional_unit and not prop.unit:
-                    result['unit_of_measurement'] = prop_optional_unit
-
+                result['unit_of_measurement'] = prop_optional_unit
         return result
 
     def spec_transform(self) -> None:
@@ -559,9 +556,10 @@ def spec_transform(self) -> None:
                     if 'state_class' in prop_entity:
                         prop.state_class = prop_entity['state_class']
                     if 'unit_of_measurement' in prop_entity:
-                        prop.external_unit = self.unit_convert(prop_entity['unit_of_measurement'])
-                        prop.icon = self.icon_convert(prop_entity['unit_of_measurement'])
-                        
+                        prop.external_unit = self.unit_convert(
+                            prop_entity['unit_of_measurement'])
+                        prop.icon = self.icon_convert(
+                            prop_entity['unit_of_measurement']) 
                 # general conversion
                 if not prop.platform:
                     if prop.writable: