diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -877,7 +877,7 @@ static CommandCost CheckFlatLandAirport(
  * @param numtracks Number of platforms.
  * @return The cost in case of success, or an error code if it failed.
  */
-static CommandCost CheckFlatLandRailStation(TileArea tile_area, DoCommandFlag flags, Axis axis, StationID *station, RailType rt, std::vector<Train *> &affected_vehicles, StationClassID spec_class, byte spec_index, byte plat_len, byte numtracks)
+static CommandCost CheckFlatLandRailStation(TileArea tile_area, DoCommandFlag flags, Axis axis, StationID *station, RailType rt, std::vector<Train *> &affected_vehicles, StationClassID spec_class, uint16_t spec_index, byte plat_len, byte numtracks)
 {
 	CommandCost cost(EXPENSES_CONSTRUCTION);
 	int allowed_z = -1;
@@ -1261,7 +1261,7 @@ static void RestoreTrainReservation(Trai
  * @param numtracks Number of platforms.
  * @return The cost in case of success, or an error code if it failed.
  */
-static CommandCost CalculateRailStationCost(TileArea tile_area, DoCommandFlag flags, Axis axis, StationID *station, RailType rt, std::vector<Train *> &affected_vehicles, StationClassID spec_class, byte spec_index, byte plat_len, byte numtracks)
+static CommandCost CalculateRailStationCost(TileArea tile_area, DoCommandFlag flags, Axis axis, StationID *station, RailType rt, std::vector<Train *> &affected_vehicles, StationClassID spec_class, uint16_t spec_index, byte plat_len, byte numtracks)
 {
 	CommandCost cost(EXPENSES_CONSTRUCTION);
 	bool length_price_ready = true;
@@ -1310,7 +1310,7 @@ static CommandCost CalculateRailStationC
  * @param adjacent allow stations directly adjacent to other stations.
  * @return the cost of this operation or an error
  */
-CommandCost CmdBuildRailStation(DoCommandFlag flags, TileIndex tile_org, RailType rt, Axis axis, byte numtracks, byte plat_len, StationClassID spec_class, byte spec_index, StationID station_to_join, bool adjacent)
+CommandCost CmdBuildRailStation(DoCommandFlag flags, TileIndex tile_org, RailType rt, Axis axis, byte numtracks, byte plat_len, StationClassID spec_class, uint16_t spec_index, StationID station_to_join, bool adjacent)
 {
 	/* Does the authority allow this? */
 	CommandCost ret = CheckIfAuthorityAllowsNewStation(tile_org, flags);
@@ -1917,7 +1917,7 @@ static CommandCost CalculateRoadStopCost
  * @return The cost of this operation or an error.
  */
 CommandCost CmdBuildRoadStop(DoCommandFlag flags, TileIndex tile, uint8 width, uint8 length, RoadStopType stop_type, bool is_drive_through,
-		DiagDirection ddir, RoadType rt, RoadStopClassID spec_class, byte spec_index, StationID station_to_join, bool adjacent)
+		DiagDirection ddir, RoadType rt, RoadStopClassID spec_class, uint16_t spec_index, StationID station_to_join, bool adjacent)
 {
 	if (!ValParamRoadType(rt) || !IsValidDiagDirection(ddir) || stop_type >= ROADSTOP_END) return CMD_ERROR;
 	bool reuse = (station_to_join != NEW_STATION);