diff --git a/src/tree_cmd.cpp b/src/tree_cmd.cpp
--- a/src/tree_cmd.cpp
+++ b/src/tree_cmd.cpp
@@ -333,7 +333,7 @@ CommandCost CmdPlantTree(TileIndex tile,
 
 	if (p2 >= MapSize()) return CMD_ERROR;
 	/* Check the tree type. It can be random or some valid value within the current climate */
-	if (p1 != (uint)-1 && p1 - _tree_base_by_landscape[_settings_game.game_creation.landscape] >= _tree_count_by_landscape[_settings_game.game_creation.landscape]) return CMD_ERROR;
+	if (p1 != UINT_MAX && p1 - _tree_base_by_landscape[_settings_game.game_creation.landscape] >= _tree_count_by_landscape[_settings_game.game_creation.landscape]) return CMD_ERROR;
 
 	// make sure sx,sy are smaller than ex,ey
 	ex = TileX(tile);