diff --git a/homeassistant/components/mill/sensor.py b/homeassistant/components/mill/sensor.py
index a8b4554139f..5241f95abdb 100644
--- a/homeassistant/components/mill/sensor.py
+++ b/homeassistant/components/mill/sensor.py
@@ -2,7 +2,7 @@
 
 from homeassistant.components.sensor import (
     DEVICE_CLASS_ENERGY,
-    STATE_CLASS_MEASUREMENT,
+    STATE_CLASS_TOTAL,
     SensorEntity,
 )
 from homeassistant.const import ENERGY_KILO_WATT_HOUR
@@ -27,17 +27,18 @@ async def async_setup_entry(hass, entry, async_add_entities):
 class MillHeaterEnergySensor(SensorEntity):
     """Representation of a Mill Sensor device."""
 
+    _attr_device_class = DEVICE_CLASS_ENERGY
+    _attr_native_unit_of_measurement = ENERGY_KILO_WATT_HOUR
+    _attr_state_class = STATE_CLASS_TOTAL
+
     def __init__(self, heater, mill_data_connection, sensor_type):
         """Initialize the sensor."""
         self._id = heater.device_id
         self._conn = mill_data_connection
         self._sensor_type = sensor_type
 
-        self._attr_device_class = DEVICE_CLASS_ENERGY
         self._attr_name = f"{heater.name} {sensor_type.replace('_', ' ')}"
         self._attr_unique_id = f"{heater.device_id}_{sensor_type}"
-        self._attr_native_unit_of_measurement = ENERGY_KILO_WATT_HOUR
-        self._attr_state_class = STATE_CLASS_MEASUREMENT
         self._attr_device_info = {
             "identifiers": {(DOMAIN, heater.device_id)},
             "name": self.name,