diff --git a/src/world/World.php b/src/world/World.php
index 5474aba61..0af46a4f9 100644
--- a/src/world/World.php
+++ b/src/world/World.php
@@ -2091,7 +2091,7 @@ class World implements ChunkManager{
 	/**
 	 * Returns the chunks adjacent to the specified chunk.
 	 *
-	 * @return (Chunk|null)[]
+	 * @return Chunk[]|null[]
 	 */
 	public function getAdjacentChunks(int $x, int $z) : array{
 		$result = [];
diff --git a/src/world/generator/PopulationTask.php b/src/world/generator/PopulationTask.php
index 7ed3abcc7..fe5f6fc8a 100644
--- a/src/world/generator/PopulationTask.php
+++ b/src/world/generator/PopulationTask.php
@@ -35,8 +35,6 @@ use function array_map;
 use function igbinary_serialize;
 use function igbinary_unserialize;
 use function intdiv;
-use function is_array;
-use function is_string;
 
 class PopulationTask extends AsyncTask{
 	private const TLS_KEY_WORLD = "world";