diff --git a/src/tree_cmd.cpp b/src/tree_cmd.cpp
--- a/src/tree_cmd.cpp
+++ b/src/tree_cmd.cpp
@@ -388,7 +388,7 @@ CommandCost CmdPlantTree(TileIndex tile,
 						}
 					}
 
-					if (_game_mode != GM_EDITOR && IsValidCompanyID(_current_company)) {
+					if (_game_mode != GM_EDITOR && Company::IsValidID(_current_company)) {
 						Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
 						if (t != NULL) ChangeTownRating(t, RATING_TREE_UP_STEP, RATING_TREE_MAXIMUM, flags);
 					}
@@ -531,7 +531,7 @@ static CommandCost ClearTile_Trees(TileI
 {
 	uint num;
 
-	if (IsValidCompanyID(_current_company)) {
+	if (Company::IsValidID(_current_company)) {
 		Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
 		if (t != NULL) ChangeTownRating(t, RATING_TREE_DOWN_STEP, RATING_TREE_MINIMUM, flags);
 	}