diff --git a/homeassistant/components/decora_wifi/light.py b/homeassistant/components/decora_wifi/light.py
index 4f1f9f059d8..84caf0ad29a 100644
--- a/homeassistant/components/decora_wifi/light.py
+++ b/homeassistant/components/decora_wifi/light.py
@@ -96,6 +96,7 @@ class DecoraWifiLight(LightEntity):
     def __init__(self, switch):
         """Initialize the switch."""
         self._switch = switch
+        self._attr_unique_id = switch.serial
 
     @property
     def supported_features(self):