diff --git a/planning/sampling_based_planner/autoware_path_sampler/include/autoware_path_sampler/utils/trajectory_utils.hpp b/planning/sampling_based_planner/autoware_path_sampler/include/autoware_path_sampler/utils/trajectory_utils.hpp
index edcb8c2b22061..c44338aa64ce8 100644
--- a/planning/sampling_based_planner/autoware_path_sampler/include/autoware_path_sampler/utils/trajectory_utils.hpp
+++ b/planning/sampling_based_planner/autoware_path_sampler/include/autoware_path_sampler/utils/trajectory_utils.hpp
@@ -140,10 +140,10 @@ size_t findEgoSegmentIndex(
 }
 
 std::vector<TrajectoryPoint> resampleTrajectoryPoints(
-  const std::vector<TrajectoryPoint> traj_points, const double interval);
+  const std::vector<TrajectoryPoint> & traj_points, const double interval);
 
 std::vector<TrajectoryPoint> resampleTrajectoryPointsWithoutStopPoint(
-  const std::vector<TrajectoryPoint> traj_points, const double interval);
+  const std::vector<TrajectoryPoint> & traj_points, const double interval);
 
 template <typename T>
 std::optional<size_t> updateFrontPointForFix(
diff --git a/planning/sampling_based_planner/autoware_path_sampler/src/utils/trajectory_utils.cpp b/planning/sampling_based_planner/autoware_path_sampler/src/utils/trajectory_utils.cpp
index c8ca80b95d284..89120eef0f76a 100644
--- a/planning/sampling_based_planner/autoware_path_sampler/src/utils/trajectory_utils.cpp
+++ b/planning/sampling_based_planner/autoware_path_sampler/src/utils/trajectory_utils.cpp
@@ -59,7 +59,7 @@ void compensateLastPose(
 }
 
 std::vector<TrajectoryPoint> resampleTrajectoryPoints(
-  const std::vector<TrajectoryPoint> traj_points, const double interval)
+  const std::vector<TrajectoryPoint> & traj_points, const double interval)
 {
   constexpr bool enable_resampling_stop_point = true;
 
@@ -71,7 +71,7 @@ std::vector<TrajectoryPoint> resampleTrajectoryPoints(
 
 // NOTE: stop point will not be resampled
 std::vector<TrajectoryPoint> resampleTrajectoryPointsWithoutStopPoint(
-  const std::vector<TrajectoryPoint> traj_points, const double interval)
+  const std::vector<TrajectoryPoint> & traj_points, const double interval)
 {
   constexpr bool enable_resampling_stop_point = false;