diff --git a/SegTracker.py b/SegTracker.py
index 8cf53809..761d7a79 100644
--- a/SegTracker.py
+++ b/SegTracker.py
@@ -141,8 +141,9 @@ def find_new_objs(self, track_mask, seg_mask):
                 or obj_num > self.max_obj_num:
                 new_obj_mask[new_obj_mask==idx] = 0
             else:
-                new_obj_mask[new_obj_mask==idx] = obj_num
                 obj_num += 1
+                new_obj_mask[new_obj_mask==idx] = obj_num
+
         return new_obj_mask
         
     def restart_tracker(self):