diff --git a/src/terraform_gui.cpp b/src/terraform_gui.cpp
--- a/src/terraform_gui.cpp
+++ b/src/terraform_gui.cpp
@@ -60,7 +60,7 @@ static void GenerateDesertArea(TileIndex
 	BEGIN_TILE_LOOP(tile, size_x, size_y, TileXY(sx, sy)) {
 		if (GetTileType(tile) != MP_WATER) {
 			SetTropicZone(tile, (_ctrl_pressed) ? TROPICZONE_NORMAL : TROPICZONE_DESERT);
-			DoCommandP(tile, 0, 0, NULL, CMD_LANDSCAPE_CLEAR);
+			DoCommandP(tile, 0, 0, CMD_LANDSCAPE_CLEAR);
 			MarkTileDirtyByTile(tile);
 		}
 	} END_TILE_LOOP(tile, size_x, size_y, 0);
@@ -114,16 +114,16 @@ bool GUIPlaceProcDragXY(ViewportDragDrop
 {
 	switch (proc) {
 		case DDSP_DEMOLISH_AREA:
-			DoCommandP(end_tile, start_tile, 0, CcPlaySound10, CMD_CLEAR_AREA | CMD_MSG(STR_00B5_CAN_T_CLEAR_THIS_AREA));
+			DoCommandP(end_tile, start_tile, 0, CMD_CLEAR_AREA | CMD_MSG(STR_00B5_CAN_T_CLEAR_THIS_AREA), CcPlaySound10);
 			break;
 		case DDSP_RAISE_AND_LEVEL_AREA:
-			DoCommandP(end_tile, start_tile, 1, CcTerraform, CMD_LEVEL_LAND | CMD_MSG(STR_0808_CAN_T_RAISE_LAND_HERE));
+			DoCommandP(end_tile, start_tile, 1, CMD_LEVEL_LAND | CMD_MSG(STR_0808_CAN_T_RAISE_LAND_HERE), CcTerraform);
 			break;
 		case DDSP_LOWER_AND_LEVEL_AREA:
-			DoCommandP(end_tile, start_tile, (uint32)-1, CcTerraform, CMD_LEVEL_LAND | CMD_MSG(STR_0809_CAN_T_LOWER_LAND_HERE));
+			DoCommandP(end_tile, start_tile, (uint32)-1, CMD_LEVEL_LAND | CMD_MSG(STR_0809_CAN_T_LOWER_LAND_HERE), CcTerraform);
 			break;
 		case DDSP_LEVEL_AREA:
-			DoCommandP(end_tile, start_tile, 0, CcPlaySound10, CMD_LEVEL_LAND | CMD_MSG(STR_CAN_T_LEVEL_LAND_HERE));
+			DoCommandP(end_tile, start_tile, 0, CMD_LEVEL_LAND | CMD_MSG(STR_CAN_T_LEVEL_LAND_HERE), CcPlaySound10);
 			break;
 		case DDSP_CREATE_ROCKS:
 			GenerateRockyArea(end_tile, start_tile);
@@ -154,7 +154,7 @@ void CcPlaySound1E(bool success, TileInd
 
 static void PlaceProc_BuyLand(TileIndex tile)
 {
-	DoCommandP(tile, 0, 0, CcPlaySound1E, CMD_PURCHASE_LAND_AREA | CMD_NO_WATER | CMD_MSG(STR_5806_CAN_T_PURCHASE_THIS_LAND));
+	DoCommandP(tile, 0, 0, CMD_PURCHASE_LAND_AREA | CMD_NO_WATER | CMD_MSG(STR_5806_CAN_T_PURCHASE_THIS_LAND), CcPlaySound1E);
 }
 
 void PlaceProc_DemolishArea(TileIndex tile)
@@ -360,7 +360,7 @@ static void CommonRaiseLowerBigLand(Tile
 		StringID msg =
 			mode ? STR_0808_CAN_T_RAISE_LAND_HERE : STR_0809_CAN_T_LOWER_LAND_HERE;
 
-		DoCommandP(tile, SLOPE_N, (uint32)mode, CcTerraform, CMD_TERRAFORM_LAND | CMD_MSG(msg));
+		DoCommandP(tile, SLOPE_N, (uint32)mode, CMD_TERRAFORM_LAND | CMD_MSG(msg), CcTerraform);
 	} else {
 		assert(_terraform_size != 0);
 		/* check out for map overflows */
@@ -387,7 +387,7 @@ static void CommonRaiseLowerBigLand(Tile
 
 		BEGIN_TILE_LOOP(tile2, sizex, sizey, tile) {
 			if (TileHeight(tile2) == h) {
-				DoCommandP(tile2, SLOPE_N, (uint32)mode, NULL, CMD_TERRAFORM_LAND);
+				DoCommandP(tile2, SLOPE_N, (uint32)mode, CMD_TERRAFORM_LAND);
 			}
 		} END_TILE_LOOP(tile2, sizex, sizey, tile)
 	}