diff --git a/homeassistant/components/wiffi/sensor.py b/homeassistant/components/wiffi/sensor.py
index b53a9140857..1036ac7986f 100644
--- a/homeassistant/components/wiffi/sensor.py
+++ b/homeassistant/components/wiffi/sensor.py
@@ -5,7 +5,7 @@ from homeassistant.components.sensor import (
     SensorStateClass,
 )
 from homeassistant.config_entries import ConfigEntry
-from homeassistant.const import DEGREE, UnitOfPressure, UnitOfTemperature
+from homeassistant.const import DEGREE, LIGHT_LUX, UnitOfPressure, UnitOfTemperature
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers.dispatcher import async_dispatcher_connect
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
@@ -33,6 +33,7 @@ UOM_MAP = {
     WIFFI_UOM_DEGREE: DEGREE,
     WIFFI_UOM_TEMP_CELSIUS: UnitOfTemperature.CELSIUS,
     WIFFI_UOM_MILLI_BAR: UnitOfPressure.MBAR,
+    WIFFI_UOM_LUX: LIGHT_LUX,
 }