diff --git a/docs/MQTT_Topics.md b/docs/MQTT_Topics.md
index 404e5e57..4f73b616 100644
--- a/docs/MQTT_Topics.md
+++ b/docs/MQTT_Topics.md
@@ -24,6 +24,9 @@ serial will be replaced with the serial number of the inverter.
 | [serial]/device/fwbuilddatetime         | R     | Build date / time of inverter firmware               |                            |
 | [serial]/device/hwpartnumber            | R     | Hardware part number of the inverter                 |                            |
 | [serial]/device/hwversion               | R     | Hardware version of the inverter                     |                            |
+| [serial]/status/reachable               | R     | Indicates whether the inverter is reachable          | 0 or 1                     |
+| [serial]/status/producing               | R     | Indicates whether the inverter is producing AC power | 0 or 1                     |
+| [serial]/status/last_update             | R     | Unix timestamp of last inverter statistics udpate    | seconds since JAN 01 1970 (UTC) |
 
 ### AC channel / global specific topics
 
@@ -62,8 +65,6 @@ cmd topics are used to set values. Status topics are updated from values set in
 | ----------------------------------------- | ----- | ---------------------------------------------------- | -------------------------- |
 | [serial]/status/limit_relative            | R     | Current applied production limit of the inverter     | % of total possible output |
 | [serial]/status/limit_absolute            | R     | Current applied production limit of the inverter     | Watt (W)                   |
-| [serial]/status/reachable                 | R     | Indicates whether the inverter is reachable          | 0 or 1                     |
-| [serial]/status/producing                 | R     | Indicates whether the inverter is producing AC power | 0 or 1                     |
 | [serial]/cmd/limit_persistent_relative    | W     | Set the inverter limit as a percentage of total production capability. The  value will survive the night without power. The updated value will show up in the web GUI and limit_relative topic immediatly. | %                          |
 | [serial]/cmd/limit_persistent_absolute    | W     | Set the inverter limit as a absolute value. The  value will survive the night without power. The updated value will show up in the web GUI and limit_relative topic after around 4 minutes. | Watt (W)                   |
 | [serial]/cmd/limit_nonpersistent_relative | W     | Set the inverter limit as a percentage of total production capability. The  value will reset to the last persistent value at night without power. The updated value will show up in the web GUI and limit_relative topic immediatly. | %                          |
diff --git a/src/MqttPublishing.cpp b/src/MqttPublishing.cpp
index 46819bce..553e2794 100644
--- a/src/MqttPublishing.cpp
+++ b/src/MqttPublishing.cpp
@@ -70,6 +70,7 @@ void MqttPublishingClass::loop()
 
             MqttSettings.publish(subtopic + "/status/reachable", String(inv->isReachable()));
             MqttSettings.publish(subtopic + "/status/producing", String(inv->isProducing()));
+            MqttSettings.publish(subtopic + "/status/last_update", String(std::time(0) - (millis() - inv->Statistics()->getLastUpdate()) / 1000));
 
             uint32_t lastUpdate = inv->Statistics()->getLastUpdate();
             if (lastUpdate > 0 && lastUpdate != _lastPublishStats[i]) {