diff --git a/source/_components/sensor.mqtt.markdown b/source/_components/sensor.mqtt.markdown
index 518d3444f09..793e7234429 100644
--- a/source/_components/sensor.mqtt.markdown
+++ b/source/_components/sensor.mqtt.markdown
@@ -31,6 +31,7 @@ Configuration variables:
 - **name** (*Optional*): The name of the sensor. Default is 'MQTT Sensor'. 
 - **qos** (*Optional*): The maximum QoS level of the state topic. Default is 0.
 - **unit_of_measurement** (*Optional*): Defines the units of measurement of the sensor, if any.
+- **expire_after** (*Optional*): Defines the number of seconds after the value expires if it's not updated. Default is 0 (=never expire).
 - **value_template** (*Optional*): Defines a [template](/topics/templating/) to extract a value from the payload.
 
 ## {% linkable_title Examples %}