diff --git a/src/timetable_cmd.cpp b/src/timetable_cmd.cpp
--- a/src/timetable_cmd.cpp
+++ b/src/timetable_cmd.cpp
@@ -166,7 +166,7 @@ CommandCost CmdSetVehicleOnTime(TileInde
 	VehicleID veh = GB(p1, 0, 20);
 
 	Vehicle *v = Vehicle::GetIfValid(veh);
-	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle() || v->orders.list == NULL) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
@@ -235,7 +235,7 @@ CommandCost CmdSetTimetableStart(TileInd
 {
 	bool timetable_all = HasBit(p1, 20);
 	Vehicle *v = Vehicle::GetIfValid(GB(p1, 0, 20));
-	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle() || v->orders.list == NULL) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
@@ -302,7 +302,7 @@ CommandCost CmdAutofillTimetable(TileInd
 	VehicleID veh = GB(p1, 0, 20);
 
 	Vehicle *v = Vehicle::GetIfValid(veh);
-	if (v == NULL || !v->IsPrimaryVehicle()) return CMD_ERROR;
+	if (v == NULL || !v->IsPrimaryVehicle() || v->orders.list == NULL) return CMD_ERROR;
 
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;