diff --git a/osi_sensordata.proto b/osi_sensordata.proto
index 18df69230..9ece68316 100644
--- a/osi_sensordata.proto
+++ b/osi_sensordata.proto
@@ -336,4 +336,15 @@ message SensorData
     // Virtual detection area of the sensor
     //
     optional VirtualDetectionArea virtual_detection_area = 28;
+
+    // The system time of the modeled source of the sensor data, given
+    // in UTC (Unix Epoch timestamp).
+    //
+    // The system time can be used to transmit the internal time of the
+    // simulated component that supplies the sensor data, which might
+    // not coincide with the simulation time as transmitted in the
+    // timestamp field. Example use cases include recorded data traces
+    // or the simulation of time synchronization mechanisms and errors.
+    //
+    optional Timestamp system_time = 29;
 }