diff --git a/src/world/World.php b/src/world/World.php
index 934ca83ca..58b2cddb6 100644
--- a/src/world/World.php
+++ b/src/world/World.php
@@ -67,7 +67,6 @@ use pocketmine\world\biome\Biome;
 use pocketmine\world\format\Chunk;
 use pocketmine\world\format\io\exception\CorruptedChunkException;
 use pocketmine\world\format\io\WritableWorldProvider;
-use pocketmine\world\generator\Generator;
 use pocketmine\world\generator\GeneratorManager;
 use pocketmine\world\generator\GeneratorRegisterTask;
 use pocketmine\world\generator\GeneratorUnregisterTask;
@@ -105,6 +104,7 @@ use function mt_rand;
 use function spl_object_id;
 use function strtolower;
 use function trim;
+use function var_dump;
 use const M_PI;
 use const PHP_INT_MAX;
 use const PHP_INT_MIN;
@@ -253,7 +253,10 @@ class World implements ChunkManager{
 	/** @var bool */
 	private $doingTick = false;
 
-	/** @var string|Generator */
+	/**
+	 * @var string
+	 * @phpstan-var class-string<\pocketmine\world\generator\Generator>
+	 */
 	private $generator;
 
 	/** @var bool */
diff --git a/src/world/format/io/FastChunkSerializer.php b/src/world/format/io/FastChunkSerializer.php
index a69ee4cbb..16883a40e 100644
--- a/src/world/format/io/FastChunkSerializer.php
+++ b/src/world/format/io/FastChunkSerializer.php
@@ -151,6 +151,7 @@ final class FastChunkSerializer{
 		$chunk->setGenerated($terrainGenerated);
 		$chunk->setPopulated($terrainPopulated);
 		$chunk->setLightPopulated($lightPopulated);
+		$chunk->clearDirtyFlags();
 
 		return $chunk;
 	}
diff --git a/src/world/generator/GeneratorRegisterTask.php b/src/world/generator/GeneratorRegisterTask.php
index 06060ae0b..831dc7852 100644
--- a/src/world/generator/GeneratorRegisterTask.php
+++ b/src/world/generator/GeneratorRegisterTask.php
@@ -32,7 +32,10 @@ use function igbinary_unserialize;
 
 class GeneratorRegisterTask extends AsyncTask{
 
-	/** @var string */
+	/**
+	 * @var string
+	 * @phpstan-var class-string<Generator>
+	 */
 	public $generatorClass;
 	/** @var string */
 	public $settings;
@@ -45,6 +48,7 @@ class GeneratorRegisterTask extends AsyncTask{
 
 	/**
 	 * @param mixed[] $generatorSettings
+	 * @phpstan-param class-string<Generator> $generatorClass
 	 * @phpstan-param array<string, mixed> $generatorSettings
 	 */
 	public function __construct(World $world, string $generatorClass, array $generatorSettings = []){
diff --git a/tests/phpstan/configs/l7-baseline.neon b/tests/phpstan/configs/l7-baseline.neon
index 1673a1c19..85e86f2f8 100644
--- a/tests/phpstan/configs/l7-baseline.neon
+++ b/tests/phpstan/configs/l7-baseline.neon
@@ -850,11 +850,6 @@ parameters:
 			count: 1
 			path: ../../../src/world/Explosion.php
 
-		-
-			message: "#^Parameter \\#2 \\$generatorClass of class pocketmine\\\\world\\\\generator\\\\GeneratorRegisterTask constructor expects string, pocketmine\\\\world\\\\generator\\\\Generator\\|string given\\.$#"
-			count: 1
-			path: ../../../src/world/World.php
-
 		-
 			message: "#^Cannot access offset 'priority' on array\\('priority' \\=\\> int, 'data' \\=\\> pocketmine\\\\math\\\\Vector3\\)\\|int\\|pocketmine\\\\math\\\\Vector3\\.$#"
 			count: 1