diff --git a/src/pocketmine/level/generator/object/Tree.php b/src/pocketmine/level/generator/object/Tree.php
index e32b77635..27b810729 100644
--- a/src/pocketmine/level/generator/object/Tree.php
+++ b/src/pocketmine/level/generator/object/Tree.php
@@ -60,7 +60,9 @@ abstract class Tree{
 			case Sapling::JUNGLE:
 				$tree = new JungleTree();
 				break;
-			case Sapling::OAK:
+			case Sapling::ACACIA:
+			case Sapling::DARK_OAK:
+				return; //TODO
 			default:
 				$tree = new OakTree();
 				/*if($random->nextRange(0, 9) === 0){