diff --git a/src/esp_sensors/mqtt.py b/src/esp_sensors/mqtt.py
index f9351e1..67fe2e5 100644
--- a/src/esp_sensors/mqtt.py
+++ b/src/esp_sensors/mqtt.py
@@ -130,7 +130,7 @@ def publish_sensor_data(
         data = {
             "temperature": temperature,
             "humidity": humidity,
-            "timestamp": time.time(),
+            "uptime": time.time(),
             "unit": sensor.unit,
         }
         client.publish(data_topic, json.dumps(data).encode())