diff --git a/homeassistant/components/switch/mqtt.py b/homeassistant/components/switch/mqtt.py
index 1169e5a3d5d..95f9a779327 100644
--- a/homeassistant/components/switch/mqtt.py
+++ b/homeassistant/components/switch/mqtt.py
@@ -34,6 +34,7 @@ PLATFORM_SCHEMA = mqtt.MQTT_RW_PLATFORM_SCHEMA.extend({
     vol.Optional(CONF_PAYLOAD_ON, default=DEFAULT_PAYLOAD_ON): cv.string,
     vol.Optional(CONF_PAYLOAD_OFF, default=DEFAULT_PAYLOAD_OFF): cv.string,
     vol.Optional(CONF_OPTIMISTIC, default=DEFAULT_OPTIMISTIC): cv.boolean,
+    vol.Optional(CONF_AVAILABILITY_TOPIC): mqtt.valid_subscribe_topic,
 })