diff --git a/homeassistant/components/utility_meter/sensor.py b/homeassistant/components/utility_meter/sensor.py
index 9a4ed9e7782..6b25ec7d123 100644
--- a/homeassistant/components/utility_meter/sensor.py
+++ b/homeassistant/components/utility_meter/sensor.py
@@ -145,13 +145,7 @@ class UtilityMeterSensor(RestoreEntity):
         ):
             return
 
-        if (
-            self._unit_of_measurement is None
-            and new_state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) is not None
-        ):
-            self._unit_of_measurement = new_state.attributes.get(
-                ATTR_UNIT_OF_MEASUREMENT
-            )
+        self._unit_of_measurement = new_state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
 
         try:
             diff = Decimal(new_state.state) - Decimal(old_state.state)