diff --git a/tree_cmd.c b/tree_cmd.c
--- a/tree_cmd.c
+++ b/tree_cmd.c
@@ -265,7 +265,7 @@ int32 CmdPlantTree(TileIndex tile, uint3
 						TreeType treetype;
 						uint growth;
 
-						if (_game_mode != GM_EDITOR && _current_player < MAX_PLAYERS) {
+						if (_game_mode != GM_EDITOR && IsValidPlayer(_current_player)) {
 							Town *t = ClosestTownFromTile(tile, _patches.dist_local_authority);
 							if (t != NULL)
 								ChangeTownRating(t, RATING_TREE_UP_STEP, RATING_TREE_MAXIMUM);
@@ -415,7 +415,7 @@ static int32 ClearTile_Trees(TileIndex t
 {
 	uint num;
 
-	if (flags & DC_EXEC && _current_player < MAX_PLAYERS) {
+	if ((flags & DC_EXEC) && IsValidPlayer(_current_player)) {
 		Town *t = ClosestTownFromTile(tile, _patches.dist_local_authority);
 		if (t != NULL)
 			ChangeTownRating(t, RATING_TREE_DOWN_STEP, RATING_TREE_MINIMUM);