diff --git a/homeassistant/components/smappee/sensor.py b/homeassistant/components/smappee/sensor.py
index 276248fd6ae..ccae097e53f 100644
--- a/homeassistant/components/smappee/sensor.py
+++ b/homeassistant/components/smappee/sensor.py
@@ -250,6 +250,7 @@ async def async_setup_entry(hass, config_entry, async_add_entities):
                     description=SmappeeSensorEntityDescription(
                         key="load",
                         name=measurement.name,
+                        native_unit_of_measurement=POWER_WATT,
                         sensor_id=measurement_id,
                         device_class=DEVICE_CLASS_POWER,
                         state_class=STATE_CLASS_MEASUREMENT,