diff --git a/homeassistant/components/binary_sensor/demo.py b/homeassistant/components/binary_sensor/demo.py
index a24b893c610..22eeaa7b8a5 100644
--- a/homeassistant/components/binary_sensor/demo.py
+++ b/homeassistant/components/binary_sensor/demo.py
@@ -41,3 +41,4 @@ class DemoBinarySensor(BinarySensorDevice):
     def is_on(self):
         """ True if the binary sensor is on. """
         return self._state
+