diff --git a/src/utils/Config.php b/src/utils/Config.php
index f15bfe1e5..3fa78df80 100644
--- a/src/utils/Config.php
+++ b/src/utils/Config.php
@@ -74,23 +74,19 @@ class Config{
 	 * @var mixed[]
 	 * @phpstan-var array<string, mixed>
 	 */
-	private $config = [];
+	private array $config = [];
 
 	/**
 	 * @var mixed[]
 	 * @phpstan-var array<string, mixed>
 	 */
-	private $nestedCache = [];
+	private array $nestedCache = [];
 
-	/** @var string */
-	private $file;
-	/** @var int */
-	private $type = Config::DETECT;
-	/** @var int */
-	private $jsonOptions = JSON_PRETTY_PRINT | JSON_BIGINT_AS_STRING;
+	private string $file;
+	private int $type = Config::DETECT;
+	private int $jsonOptions = JSON_PRETTY_PRINT | JSON_BIGINT_AS_STRING;
 
-	/** @var bool */
-	private $changed = false;
+	private bool $changed = false;
 
 	/** @var int[] */
 	public static $formats = [
diff --git a/src/utils/Filesystem.php b/src/utils/Filesystem.php
index 56d45790e..3a4ef243f 100644
--- a/src/utils/Filesystem.php
+++ b/src/utils/Filesystem.php
@@ -61,12 +61,12 @@ use const SCANDIR_SORT_NONE;
 
 final class Filesystem{
 	/** @var resource[] */
-	private static $lockFileHandles = [];
+	private static array $lockFileHandles = [];
 	/**
 	 * @var string[]
 	 * @phpstan-var array<string, string>
 	 */
-	private static $cleanedPaths = [
+	private static array $cleanedPaths = [
 		\pocketmine\PATH => self::CLEAN_PATH_SRC_PREFIX
 	];
 
diff --git a/src/utils/InternetRequestResult.php b/src/utils/InternetRequestResult.php
index 481ceedb3..c952c2d6b 100644
--- a/src/utils/InternetRequestResult.php
+++ b/src/utils/InternetRequestResult.php
@@ -24,26 +24,15 @@ declare(strict_types=1);
 namespace pocketmine\utils;
 
 final class InternetRequestResult{
-
-	/**
-	 * @var string[][]
-	 * @phpstan-var list<array<string, string>>
-	 */
-	private $headers;
-	/** @var string */
-	private $body;
-	/** @var int */
-	private $code;
-
 	/**
 	 * @param string[][] $headers
 	 * @phpstan-param list<array<string, string>> $headers
 	 */
-	public function __construct(array $headers, string $body, int $code){
-		$this->headers = $headers;
-		$this->body = $body;
-		$this->code = $code;
-	}
+	public function __construct(
+		private array $headers,
+		private string $body,
+		private int $code
+	){}
 
 	/**
 	 * @return string[][]
diff --git a/src/utils/Random.php b/src/utils/Random.php
index 3c7f6cb0d..6e932a079 100644
--- a/src/utils/Random.php
+++ b/src/utils/Random.php
@@ -35,17 +35,10 @@ class Random{
 	public const Z = 521288629;
 	public const W = 88675123;
 
-	/** @var int */
-	private $x;
-
-	/** @var int */
-	private $y;
-
-	/** @var int */
-	private $z;
-
-	/** @var int */
-	private $w;
+	private int $x;
+	private int $y;
+	private int $z;
+	private int $w;
 
 	/** @var int */
 	protected $seed;
diff --git a/src/utils/Terminal.php b/src/utils/Terminal.php
index 955abc660..c89ad7805 100644
--- a/src/utils/Terminal.php
+++ b/src/utils/Terminal.php
@@ -60,8 +60,7 @@ abstract class Terminal{
 	public static string $COLOR_WHITE = "";
 	public static string $COLOR_MINECOIN_GOLD = "";
 
-	/** @var bool|null */
-	private static $formattingCodes = null;
+	private static ?bool $formattingCodes = null;
 
 	public static function hasFormattingCodes() : bool{
 		if(self::$formattingCodes === null){
diff --git a/src/utils/Utils.php b/src/utils/Utils.php
index adb3187f5..b44eb9bff 100644
--- a/src/utils/Utils.php
+++ b/src/utils/Utils.php
@@ -105,10 +105,8 @@ final class Utils{
 	public const OS_BSD = "bsd";
 	public const OS_UNKNOWN = "other";
 
-	/** @var string|null */
-	private static $os;
-	/** @var UuidInterface|null */
-	private static $serverUniqueId = null;
+	private static ?string $os;
+	private static ?UuidInterface $serverUniqueId = null;
 
 	/**
 	 * Returns a readable identifier for the given Closure, including file and line.
diff --git a/src/utils/VersionString.php b/src/utils/VersionString.php
index 0b2aed47a..2d2cb6bca 100644
--- a/src/utils/VersionString.php
+++ b/src/utils/VersionString.php
@@ -30,28 +30,16 @@ use function preg_match;
  * Manages PocketMine-MP version strings, and compares them
  */
 class VersionString{
-	/** @var string */
-	private $baseVersion;
-	/** @var string */
-	private $suffix;
-
-	/** @var int */
-	private $major;
-	/** @var int */
-	private $minor;
-	/** @var int */
-	private $patch;
-
-	/** @var int */
-	private $build;
-	/** @var bool */
-	private $development = false;
-
-	public function __construct(string $baseVersion, bool $isDevBuild = false, int $buildNumber = 0){
-		$this->baseVersion = $baseVersion;
-		$this->development = $isDevBuild;
-		$this->build = $buildNumber;
+	private int $major;
+	private int $minor;
+	private int $patch;
+	private string $suffix;
 
+	public function __construct(
+		private string $baseVersion,
+		private bool $isDevBuild = false,
+		private int $buildNumber = 0
+	){
 		preg_match('/^(\d+)\.(\d+)\.(\d+)(?:-(.*))?$/', $this->baseVersion, $matches);
 		if(count($matches) < 4){
 			throw new \InvalidArgumentException("Invalid base version \"$baseVersion\", should contain at least 3 version digits");
@@ -77,10 +65,10 @@ class VersionString{
 
 	public function getFullVersion(bool $build = false) : string{
 		$retval = $this->baseVersion;
-		if($this->development){
+		if($this->isDevBuild){
 			$retval .= "+dev";
-			if($build && $this->build > 0){
-				$retval .= "." . $this->build;
+			if($build && $this->buildNumber > 0){
+				$retval .= "." . $this->buildNumber;
 			}
 		}
 
@@ -104,11 +92,11 @@ class VersionString{
 	}
 
 	public function getBuild() : int{
-		return $this->build;
+		return $this->buildNumber;
 	}
 
 	public function isDev() : bool{
-		return $this->development;
+		return $this->isDevBuild;
 	}
 
 	public function __toString() : string{