diff --git a/launch/rsp.launch.py b/launch/rsp.launch.py
index 7a0bc33..c6b2afe 100644
--- a/launch/rsp.launch.py
+++ b/launch/rsp.launch.py
@@ -3,7 +3,7 @@ import os
 from ament_index_python.packages import get_package_share_directory
 
 from launch import LaunchDescription
-from launch.substitutions import LaunchConfiguration
+from launch.substitutions import LaunchConfiguration, Command, FindExecutable, PathJoinSubstitution
 from launch.actions import DeclareLaunchArgument
 from launch_ros.actions import Node