diff --git a/homeassistant/components/mqtt/__init__.py b/homeassistant/components/mqtt/__init__.py
index 37a7a63c72b..b5ea258c5cc 100644
--- a/homeassistant/components/mqtt/__init__.py
+++ b/homeassistant/components/mqtt/__init__.py
@@ -30,7 +30,7 @@ DEFAULT_QOS = 0
 DEFAULT_RETAIN = False
 
 SERVICE_PUBLISH = 'publish'
-EVENT_MQTT_MESSAGE_RECEIVED = 'MQTT_MESSAGE_RECEIVED'
+EVENT_MQTT_MESSAGE_RECEIVED = 'mqtt_message_received'
 
 REQUIREMENTS = ['paho-mqtt==1.1']