diff --git a/AntennaTracker/GCS_Mavlink.cpp b/AntennaTracker/GCS_Mavlink.cpp
index 2f6ae171b6..3a509d9d9f 100644
--- a/AntennaTracker/GCS_Mavlink.cpp
+++ b/AntennaTracker/GCS_Mavlink.cpp
@@ -386,7 +386,7 @@ void GCS_MAVLINK_Tracker::mavlink_check_target(const mavlink_message_t &msg)
 
     // set our sysid to the target, this ensures we lock onto a single vehicle
     if (tracker.g.sysid_target == 0) {
-        tracker.g.sysid_target = msg.sysid;
+        tracker.g.sysid_target.set(msg.sysid);
     }
 
     // send data stream request to target on all channels