diff --git a/homeassistant/components/mqtt/const.py b/homeassistant/components/mqtt/const.py
index 1dc25c1e78c..dc8aa2f2c74 100644
--- a/homeassistant/components/mqtt/const.py
+++ b/homeassistant/components/mqtt/const.py
@@ -19,6 +19,7 @@ CONF_ENCODING = "encoding"
 CONF_KEEPALIVE = "keepalive"
 CONF_QOS = ATTR_QOS
 CONF_RETAIN = ATTR_RETAIN
+CONF_SCHEMA = "schema"
 CONF_STATE_TOPIC = "state_topic"
 CONF_STATE_VALUE_TEMPLATE = "state_value_template"
 CONF_TOPIC = "topic"
diff --git a/homeassistant/components/mqtt/light/schema.py b/homeassistant/components/mqtt/light/schema.py
index a7ab5e986a7..6e2ac60b28d 100644
--- a/homeassistant/components/mqtt/light/schema.py
+++ b/homeassistant/components/mqtt/light/schema.py
@@ -1,7 +1,7 @@
 """Shared schema code."""
 import voluptuous as vol
 
-CONF_SCHEMA = "schema"
+from ..const import CONF_SCHEMA
 
 MQTT_LIGHT_SCHEMA_SCHEMA = vol.Schema(
     {
diff --git a/homeassistant/components/mqtt/vacuum/schema.py b/homeassistant/components/mqtt/vacuum/schema.py
index 949b5cede9c..d2ed91fa631 100644
--- a/homeassistant/components/mqtt/vacuum/schema.py
+++ b/homeassistant/components/mqtt/vacuum/schema.py
@@ -1,7 +1,8 @@
 """Shared schema code."""
 import voluptuous as vol
 
-CONF_SCHEMA = "schema"
+from ..const import CONF_SCHEMA
+
 LEGACY = "legacy"
 STATE = "state"