diff --git a/perception/autoware_multi_object_tracker/src/debugger/debug_object.cpp b/perception/autoware_multi_object_tracker/src/debugger/debug_object.cpp
index 58b7dfc5cef48..59f50bd2e9f0b 100644
--- a/perception/autoware_multi_object_tracker/src/debugger/debug_object.cpp
+++ b/perception/autoware_multi_object_tracker/src/debugger/debug_object.cpp
@@ -51,7 +51,7 @@ int32_t uuidToInt(const boost::uuids::uuid & uuid)
 namespace autoware::multi_object_tracker
 {
 
-TrackerObjectDebugger::TrackerObjectDebugger(std::string frame_id)
+TrackerObjectDebugger::TrackerObjectDebugger(const std::string & frame_id)
 {
   // set frame id
   frame_id_ = frame_id;
@@ -173,7 +173,7 @@ void TrackerObjectDebugger::process()
 }
 
 void TrackerObjectDebugger::draw(
-  const std::vector<std::vector<ObjectData>> object_data_groups,
+  const std::vector<std::vector<ObjectData>> & object_data_groups,
   visualization_msgs::msg::MarkerArray & marker_array) const
 {
   // initialize markers
diff --git a/perception/autoware_multi_object_tracker/src/debugger/debug_object.hpp b/perception/autoware_multi_object_tracker/src/debugger/debug_object.hpp
index ed4c556959861..c77b465fb2bc9 100644
--- a/perception/autoware_multi_object_tracker/src/debugger/debug_object.hpp
+++ b/perception/autoware_multi_object_tracker/src/debugger/debug_object.hpp
@@ -65,7 +65,7 @@ struct ObjectData
 class TrackerObjectDebugger
 {
 public:
-  explicit TrackerObjectDebugger(std::string frame_id);
+  explicit TrackerObjectDebugger(const std::string & frame_id);
 
 private:
   bool is_initialized_{false};
@@ -96,7 +96,7 @@ class TrackerObjectDebugger
 
   void reset();
   void draw(
-    const std::vector<std::vector<ObjectData>> object_data_groups,
+    const std::vector<std::vector<ObjectData>> & object_data_groups,
     visualization_msgs::msg::MarkerArray & marker_array) const;
   void process();
   void getMessage(visualization_msgs::msg::MarkerArray & marker_array) const;