diff --git a/homeassistant/components/tomorrowio/sensor.py b/homeassistant/components/tomorrowio/sensor.py
index 947bbf6fd2f540f1c0ebc2a77103edc6c928e522..88b5af79604646aa73896eb8ec79869b2615337a 100644
--- a/homeassistant/components/tomorrowio/sensor.py
+++ b/homeassistant/components/tomorrowio/sensor.py
@@ -92,8 +92,9 @@ class TomorrowioSensorEntityDescription(SensorEntityDescription):
             )
 
         if self.value_map is not None:
-            self.device_class = SensorDeviceClass.ENUM
-            self.options = [item.name.lower() for item in self.value_map]
+            options = [item.name.lower() for item in self.value_map]
+            object.__setattr__(self, "device_class", SensorDeviceClass.ENUM)
+            object.__setattr__(self, "options", options)
 
 
 # From https://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.files/fileID/14285