diff --git a/play_motion2/include/play_motion2/motion_loader.hpp b/play_motion2/include/play_motion2/motion_loader.hpp
index b8003b3..4b6cc9b 100644
--- a/play_motion2/include/play_motion2/motion_loader.hpp
+++ b/play_motion2/include/play_motion2/motion_loader.hpp
@@ -16,6 +16,7 @@
 #define PLAY_MOTION2__MOTION_LOADER_HPP_
 
 #include <string>
+#include <functional>
 
 #include "play_motion2/types.hpp"
 #include "play_motion2_msgs/msg/motion.hpp"
diff --git a/play_motion2/include/play_motion2/play_motion2.hpp b/play_motion2/include/play_motion2/play_motion2.hpp
index d0d16cd..dc9d099 100644
--- a/play_motion2/include/play_motion2/play_motion2.hpp
+++ b/play_motion2/include/play_motion2/play_motion2.hpp
@@ -19,6 +19,7 @@
 #include <memory>
 #include <string>
 #include <vector>
+#include <functional>
 
 #include "play_motion2/motion_loader.hpp"
 #include "play_motion2/motion_planner.hpp"