diff --git a/src/timetable_cmd.cpp b/src/timetable_cmd.cpp
--- a/src/timetable_cmd.cpp
+++ b/src/timetable_cmd.cpp
@@ -20,6 +20,8 @@
 
 #include "table/strings.h"
 
+#include "safeguards.h"
+
 /**
  * Change/update a particular timetable entry.
  * @param v            The vehicle to change the timetable of.