diff --git a/homeassistant/components/mill/climate.py b/homeassistant/components/mill/climate.py
index d0b15f5d8ff..2e7b22da833 100644
--- a/homeassistant/components/mill/climate.py
+++ b/homeassistant/components/mill/climate.py
@@ -99,6 +99,7 @@ class MillHeater(CoordinatorEntity[MillDataUpdateCoordinator], ClimateEntity):
     )
     _attr_target_temperature_step = PRECISION_TENTHS
     _attr_temperature_unit = UnitOfTemperature.CELSIUS
+    _enable_turn_on_off_backwards_compatibility = False
 
     def __init__(
         self, coordinator: MillDataUpdateCoordinator, heater: mill.Heater