diff --git a/src/timetable.h b/src/timetable.h
--- a/src/timetable.h
+++ b/src/timetable.h
@@ -10,6 +10,7 @@
 #ifndef TIMETABLE_H
 #define TIMETABLE_H
 
+#include "timer/timer_game_tick.h"
 #include "date_type.h"
 #include "timer/timer_game_calendar.h"
 #include "vehicle_type.h"
@@ -18,6 +19,6 @@ static const TimerGameCalendar::Year MAX
 
 void ShowTimetableWindow(const Vehicle *v);
 void UpdateVehicleTimetable(Vehicle *v, bool travelling);
-void SetTimetableParams(int param1, int param2, Ticks ticks);
+void SetTimetableParams(int param1, int param2, TimerGameTick::Ticks ticks);
 
 #endif /* TIMETABLE_H */