diff --git a/homeassistant/components/mqtt/discovery.py b/homeassistant/components/mqtt/discovery.py
index ca2d37bbbba..fa29f03c5e5 100644
--- a/homeassistant/components/mqtt/discovery.py
+++ b/homeassistant/components/mqtt/discovery.py
@@ -20,7 +20,8 @@ _LOGGER = logging.getLogger(__name__)
 
 TOPIC_MATCHER = re.compile(
     r'homeassistant/(?P<component>\w+)/(?P<object_id>\w+)/config')
-SUPPORTED_COMPONENTS = ['binary_sensor']
+
+SUPPORTED_COMPONENTS = ['binary_sensor', 'sensor']
 
 
 @callback
@@ -39,8 +40,7 @@ def async_start(hass, discovery_topic, hass_config):
         try:
             payload = json.loads(payload)
         except ValueError:
-            _LOGGER.warning(
-                "Unable to parse JSON %s: %s", object_id, payload)
+            _LOGGER.warning("Unable to parse JSON %s: %s", object_id, payload)
             return
 
         if component not in SUPPORTED_COMPONENTS:
diff --git a/homeassistant/components/sensor/mqtt.py b/homeassistant/components/sensor/mqtt.py
index 81267cfc45e..797f8007dc1 100644
--- a/homeassistant/components/sensor/mqtt.py
+++ b/homeassistant/components/sensor/mqtt.py
@@ -29,7 +29,10 @@ PLATFORM_SCHEMA = mqtt.MQTT_RO_PLATFORM_SCHEMA.extend({
 
 # pylint: disable=unused-argument
 def setup_platform(hass, config, add_devices, discovery_info=None):
-    """Setup MQTT Sensor."""
+    """Set up MQTT Sensor."""
+    if discovery_info is not None:
+        config = PLATFORM_SCHEMA(discovery_info)
+
     value_template = config.get(CONF_VALUE_TEMPLATE)
     if value_template is not None:
         value_template.hass = hass