diff --git a/include/tracker.h b/include/tracker.h
index 096df65d6caf0eebc158299af2bf86ad2ac7450b..39b8a60590efba0112b9f798b7c4ac8a831ae8dc 100644
--- a/include/tracker.h
+++ b/include/tracker.h
@@ -190,7 +190,7 @@ class TrackPerson : public QList<TrackPoint>
 {
 private:
     int mNr; // person number
-    int mMarkerID; //
+    int mMarkerID = -1; //markerID of Trackperson; -1 as positive values including 0 do exist as ArucoCodeNumbers-Values
     double mHeight; // height of the person
     int mHeightCount; // number of colors where mHeight is averaged
     int mFirstFrame; // 0.. frame where the person was tracked the first time
diff --git a/src/tracker.cpp b/src/tracker.cpp
index f3fa179e654b2c0c84b82be7856df9e53e30f402..a59d1c9190edcc4ca30a2af0e57586701fa37ee8 100644
--- a/src/tracker.cpp
+++ b/src/tracker.cpp
@@ -2093,7 +2093,7 @@ void TrackPerson::syncTrackPersonMarkerID(TrackPoint &tp) // usage of &pL für P
 
     if (tpMarkerID != -1) // CodeMarker was recognized
     {
-        if (mMarkerID == 0 ) // first time a Person is found TrackPerson.mMarkerID is natively zero
+        if (mMarkerID == -1) // first time a Person is found TrackPerson.mMarkerID is -1 by initialisation
         {
             setMarkerID(tpMarkerID); // set TrackPerson MarkerID equal to TrackPoint MarkerID
         }