diff --git a/src/world/generator/Flat.php b/src/world/generator/Flat.php
index fff96db94..39d782de3 100644
--- a/src/world/generator/Flat.php
+++ b/src/world/generator/Flat.php
@@ -25,6 +25,7 @@ namespace pocketmine\world\generator;
 
 use pocketmine\block\VanillaBlocks;
 use pocketmine\world\ChunkManager;
+use pocketmine\world\format\BiomeArray;
 use pocketmine\world\format\Chunk;
 use pocketmine\world\format\SubChunk;
 use pocketmine\world\generator\object\OreType;
@@ -68,14 +69,7 @@ class Flat extends Generator{
 	}
 
 	protected function generateBaseChunk() : void{
-		$this->chunk = new Chunk();
-
-		$biomeId = $this->options->getBiomeId();
-		for($Z = 0; $Z < Chunk::EDGE_LENGTH; ++$Z){
-			for($X = 0; $X < Chunk::EDGE_LENGTH; ++$X){
-				$this->chunk->setBiomeId($X, $Z, $biomeId);
-			}
-		}
+		$this->chunk = new Chunk([], BiomeArray::fill($this->options->getBiomeId()));
 
 		$structure = $this->options->getStructure();
 		$count = count($structure);