diff --git a/homeassistant/components/sensor/moon.py b/homeassistant/components/sensor/moon.py
index 3b13e625bb4..2de5b613065 100644
--- a/homeassistant/components/sensor/moon.py
+++ b/homeassistant/components/sensor/moon.py
@@ -62,11 +62,6 @@ class MoonSensor(Entity):
         else:
             return 'New moon'
 
-    @property
-    def unit_of_measurement(self):
-        """Return the unit the value is expressed in."""
-        return 'Phase'
-
     @property
     def icon(self):
         """Icon to use in the frontend, if any."""