diff --git a/src/track_func.h b/src/track_func.h
--- a/src/track_func.h
+++ b/src/track_func.h
@@ -5,6 +5,7 @@
 #ifndef TRACK_FUNC_H
 #define TRACK_FUNC_H
 
+#include "core/bitmath_func.hpp"
 #include "track_type.h"
 #include "direction_type.h"
 #include "slope_func.h"