diff --git a/src/world/format/io/FastChunkSerializer.php b/src/world/format/io/FastChunkSerializer.php
index a0ea61188..c60c1bf56 100644
--- a/src/world/format/io/FastChunkSerializer.php
+++ b/src/world/format/io/FastChunkSerializer.php
@@ -113,7 +113,6 @@ final class FastChunkSerializer{
 		$terrainPopulated = (bool) ($flags & self::FLAG_POPULATED);
 
 		$subChunks = [];
-		$biomeIds = null;
 		$heightMap = null;
 
 		$count = $stream->getByte();