diff --git a/log.capnp b/log.capnp
index 8cb5d5f..9801514 100644
--- a/log.capnp
+++ b/log.capnp
@@ -586,6 +586,7 @@ struct RadarState @0x9a185389d6fdd05f {
     aLeadTau @12 :Float32;
     modelProb @13 :Float32;
     radar @14 :Bool;
+    radarTrackId @15 :Int32 = -1;
 
     aLeadDEPRECATED @5 :Float32;
   }