diff --git a/homeassistant/components/light/rfxtrx.py b/homeassistant/components/light/rfxtrx.py
index 08f3dcc7c60a594c1c899ed34f31097d5439ff7b..91c0b14be6741aee9039b7950ab7f08eb7deec2a 100644
--- a/homeassistant/components/light/rfxtrx.py
+++ b/homeassistant/components/light/rfxtrx.py
@@ -155,13 +155,14 @@ class RfxtrxLight(Light):
     def turn_on(self, **kwargs):
         """ Turn the light on. """
         brightness = kwargs.get(ATTR_BRIGHTNESS)
+        if not self._event:
+            return
 
         if brightness is None:
             self._brightness = 100
+            self._event.device.send_on(rfxtrx.RFXOBJECT.transport)
         else:
             self._brightness = ((brightness + 4) * 100 // 255 - 1)
-
-        if hasattr(self, '_event') and self._event:
             self._event.device.send_dim(rfxtrx.RFXOBJECT.transport,
                                         self._brightness)