diff --git a/perception/multi_object_tracker/src/multi_object_tracker_core.cpp b/perception/multi_object_tracker/src/multi_object_tracker_core.cpp
index 2acc4f447cb50..014e1de779d8c 100644
--- a/perception/multi_object_tracker/src/multi_object_tracker_core.cpp
+++ b/perception/multi_object_tracker/src/multi_object_tracker_core.cpp
@@ -389,6 +389,7 @@ void MultiObjectTracker::sanitizeTracker(
   /* delete collision tracker */
   for (auto itr1 = list_tracker.begin(); itr1 != list_tracker.end(); ++itr1) {
     autoware_auto_perception_msgs::msg::TrackedObject object1;
+    bool should_delete_tracker1 = false;
     (*itr1)->getTrackedObject(time, object1);
     for (auto itr2 = std::next(itr1); itr2 != list_tracker.end(); ++itr2) {
       autoware_auto_perception_msgs::msg::TrackedObject object2;
@@ -406,7 +407,6 @@ void MultiObjectTracker::sanitizeTracker(
       const auto iou = object_recognition_utils::get2dIoU(object1, object2, min_union_iou_area);
       const auto & label1 = (*itr1)->getHighestProbLabel();
       const auto & label2 = (*itr2)->getHighestProbLabel();
-      bool should_delete_tracker1 = false;
       bool should_delete_tracker2 = false;
 
       // If at least one of them is UNKNOWN, delete the one with lower IOU. Because the UNKNOWN
@@ -434,16 +434,16 @@ void MultiObjectTracker::sanitizeTracker(
           }
         }
       }
-
-      if (should_delete_tracker1) {
-        itr1 = list_tracker.erase(itr1);
-        --itr1;
-        break;
-      } else if (should_delete_tracker2) {
+      if (should_delete_tracker2) {
         itr2 = list_tracker.erase(itr2);
         --itr2;
+        break;
       }
     }
+    if (should_delete_tracker1) {
+        itr1 = list_tracker.erase(itr1);
+        --itr1;
+    }
   }
 }