diff --git a/src/timetable_cmd.cpp b/src/timetable_cmd.cpp
--- a/src/timetable_cmd.cpp
+++ b/src/timetable_cmd.cpp
@@ -97,7 +97,7 @@ static void ChangeTimetable(Vehicle *v, 
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdChangeTimetable(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+CommandCost CmdChangeTimetable(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const std::string &text)
 {
 	VehicleID veh = GB(p1, 0, 20);
 
@@ -191,7 +191,7 @@ CommandCost CmdChangeTimetable(TileIndex
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdSetVehicleOnTime(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+CommandCost CmdSetVehicleOnTime(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const std::string &text)
 {
 	VehicleID veh = GB(p1, 0, 20);
 
@@ -258,7 +258,7 @@ static bool VehicleTimetableSorter(Vehic
  * @param text Not used.
  * @return The error or cost of the operation.
  */
-CommandCost CmdSetTimetableStart(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+CommandCost CmdSetTimetableStart(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const std::string &text)
 {
 	bool timetable_all = HasBit(p1, 20);
 	Vehicle *v = Vehicle::GetIfValid(GB(p1, 0, 20));
@@ -323,7 +323,7 @@ CommandCost CmdSetTimetableStart(TileInd
  * @param text unused
  * @return the cost of this operation or an error
  */
-CommandCost CmdAutofillTimetable(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
+CommandCost CmdAutofillTimetable(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const std::string &text)
 {
 	VehicleID veh = GB(p1, 0, 20);