diff --git a/homeassistant/components/mill/sensor.py b/homeassistant/components/mill/sensor.py
index 5b0cf7efd73..8b68d0ebe38 100644
--- a/homeassistant/components/mill/sensor.py
+++ b/homeassistant/components/mill/sensor.py
@@ -18,7 +18,7 @@ async def async_setup_entry(hass, entry, async_add_entities):
 
     dev = []
     for heater in mill_data_connection.heaters.values():
-        for sensor_type in [CONSUMPTION_TODAY, CONSUMPTION_YEAR]:
+        for sensor_type in (CONSUMPTION_TODAY, CONSUMPTION_YEAR):
             dev.append(
                 MillHeaterEnergySensor(heater, mill_data_connection, sensor_type)
             )