diff --git a/rail_cmd.c b/rail_cmd.c
index 092ed6f77c..a3124570c6 100644
--- a/rail_cmd.c
+++ b/rail_cmd.c
@@ -916,9 +916,9 @@ static int32 DoConvertRail(TileIndex tile, RailType totype, bool exec)
 	return _price.build_rail / 2;
 }
 
-extern int32 DoConvertStationRail(TileIndex tile, uint totype, bool exec);
-extern int32 DoConvertStreetRail(TileIndex tile, uint totype, bool exec);
-extern int32 DoConvertTunnelBridgeRail(TileIndex tile, uint totype, bool exec);
+extern int32 DoConvertStationRail(TileIndex tile, RailType totype, bool exec);
+extern int32 DoConvertStreetRail(TileIndex tile, RailType totype, bool exec);
+extern int32 DoConvertTunnelBridgeRail(TileIndex tile, RailType totype, bool exec);
 
 /** Convert one rail type to the other. You can convert normal rail to
  * monorail/maglev easily or vice-versa.
diff --git a/road_cmd.c b/road_cmd.c
index fc603c7e30..2614c842c1 100644
--- a/road_cmd.c
+++ b/road_cmd.c
@@ -419,7 +419,7 @@ do_clear:;
 	return cost;
 }
 
-int32 DoConvertStreetRail(TileIndex tile, uint totype, bool exec)
+int32 DoConvertStreetRail(TileIndex tile, RailType totype, bool exec)
 {
 	// not a railroad crossing?
 	if (!IsLevelCrossing(tile)) return CMD_ERROR;
diff --git a/station_cmd.c b/station_cmd.c
index 17edbd950f..8dcc1d7004 100644
--- a/station_cmd.c
+++ b/station_cmd.c
@@ -1243,7 +1243,7 @@ static int32 RemoveRailroadStation(Station *st, TileIndex tile, uint32 flags)
 	return cost;
 }
 
-int32 DoConvertStationRail(TileIndex tile, uint totype, bool exec)
+int32 DoConvertStationRail(TileIndex tile, RailType totype, bool exec)
 {
 	const Station* st = GetStationByTile(tile);
 
diff --git a/tunnelbridge_cmd.c b/tunnelbridge_cmd.c
index 9d90015153..b53388f2b0 100644
--- a/tunnelbridge_cmd.c
+++ b/tunnelbridge_cmd.c
@@ -716,7 +716,7 @@ static int32 ClearTile_TunnelBridge(TileIndex tile, byte flags)
 	return CMD_ERROR;
 }
 
-int32 DoConvertTunnelBridgeRail(TileIndex tile, uint totype, bool exec)
+int32 DoConvertTunnelBridgeRail(TileIndex tile, RailType totype, bool exec)
 {
 	TileIndex endtile;
 	uint length;