diff --git a/src/pocketmine/Collectable.php b/src/pocketmine/Collectable.php
index ece56bb0b..238cfcfe6 100644
--- a/src/pocketmine/Collectable.php
+++ b/src/pocketmine/Collectable.php
@@ -32,6 +32,9 @@ abstract class Collectable extends \Threaded{
 		return $this->isGarbage;
 	}
 
+	/**
+	 * @return void
+	 */
 	public function setGarbage(){
 		$this->isGarbage = true;
 	}
diff --git a/src/pocketmine/CrashDump.php b/src/pocketmine/CrashDump.php
index 86e335ed4..530a8d7a8 100644
--- a/src/pocketmine/CrashDump.php
+++ b/src/pocketmine/CrashDump.php
@@ -137,6 +137,9 @@ class CrashDump{
 		return $this->path;
 	}
 
+	/**
+	 * @return string
+	 */
 	public function getEncodedData(){
 		return $this->encodedData;
 	}
@@ -345,6 +348,8 @@ class CrashDump{
 
 	/**
 	 * @param string $line
+	 *
+	 * @return void
 	 */
 	public function addLine($line = ""){
 		fwrite($this->fp, $line . PHP_EOL);
@@ -352,6 +357,8 @@ class CrashDump{
 
 	/**
 	 * @param string $str
+	 *
+	 * @return void
 	 */
 	public function add($str){
 		fwrite($this->fp, $str);
diff --git a/src/pocketmine/IPlayer.php b/src/pocketmine/IPlayer.php
index bc0e8bc9d..8ea9ba59b 100644
--- a/src/pocketmine/IPlayer.php
+++ b/src/pocketmine/IPlayer.php
@@ -44,6 +44,8 @@ interface IPlayer extends ServerOperator{
 
 	/**
 	 * @param bool $banned
+	 *
+	 * @return void
 	 */
 	public function setBanned(bool $banned);
 
@@ -54,6 +56,8 @@ interface IPlayer extends ServerOperator{
 
 	/**
 	 * @param bool $value
+	 *
+	 * @return void
 	 */
 	public function setWhitelisted(bool $value);
 
diff --git a/src/pocketmine/MemoryManager.php b/src/pocketmine/MemoryManager.php
index 52e650a35..7ae331184 100644
--- a/src/pocketmine/MemoryManager.php
+++ b/src/pocketmine/MemoryManager.php
@@ -115,7 +115,7 @@ class MemoryManager{
 		$this->init();
 	}
 
-	private function init(){
+	private function init() : void{
 		$this->memoryLimit = ((int) $this->server->getProperty("memory.main-limit", 0)) * 1024 * 1024;
 
 		$defaultMemory = 1024;
@@ -201,6 +201,8 @@ class MemoryManager{
 	 * @param int  $limit
 	 * @param bool $global
 	 * @param int  $triggerCount
+	 *
+	 * @return void
 	 */
 	public function trigger(int $memory, int $limit, bool $global = false, int $triggerCount = 0){
 		$this->server->getLogger()->debug(sprintf("[Memory Manager] %sLow memory triggered, limit %gMB, using %gMB",
@@ -230,6 +232,8 @@ class MemoryManager{
 
 	/**
 	 * Called every tick to update the memory manager state.
+	 *
+	 * @return void
 	 */
 	public function check(){
 		Timings::$memoryManagerTimer->startTiming();
@@ -297,6 +301,8 @@ class MemoryManager{
 	 * @param string $outputFolder
 	 * @param int    $maxNesting
 	 * @param int    $maxStringSize
+	 *
+	 * @return void
 	 */
 	public function dumpServerMemory(string $outputFolder, int $maxNesting, int $maxStringSize){
 		$this->server->getLogger()->notice("[Dump] After the memory dump is done, the server might crash");
@@ -319,6 +325,7 @@ class MemoryManager{
 	 * @param int     $maxStringSize
 	 * @param \Logger $logger
 	 *
+	 * @return void
 	 * @throws \ReflectionException
 	 */
 	public static function dumpMemory($startingObject, string $outputFolder, int $maxNesting, int $maxStringSize, \Logger $logger){
@@ -479,7 +486,7 @@ class MemoryManager{
 	 * @param int      $maxNesting
 	 * @param int      $maxStringSize
 	 */
-	private static function continueDump($from, &$data, array &$objects, array &$refCounts, int $recursion, int $maxNesting, int $maxStringSize){
+	private static function continueDump($from, &$data, array &$objects, array &$refCounts, int $recursion, int $maxNesting, int $maxStringSize) : void{
 		if($maxNesting <= 0){
 			$data = "(error) NESTING LIMIT REACHED";
 			return;
diff --git a/src/pocketmine/OfflinePlayer.php b/src/pocketmine/OfflinePlayer.php
index 0e631ee62..18702bc92 100644
--- a/src/pocketmine/OfflinePlayer.php
+++ b/src/pocketmine/OfflinePlayer.php
@@ -57,6 +57,9 @@ class OfflinePlayer implements IPlayer, Metadatable{
 		return $this->name;
 	}
 
+	/**
+	 * @return Server
+	 */
 	public function getServer(){
 		return $this->server;
 	}
diff --git a/src/pocketmine/Thread.php b/src/pocketmine/Thread.php
index 00b76b125..c6a335a2e 100644
--- a/src/pocketmine/Thread.php
+++ b/src/pocketmine/Thread.php
@@ -36,10 +36,18 @@ abstract class Thread extends \Thread{
 	/** @var bool */
 	protected $isKilled = false;
 
+	/**
+	 * @return \ClassLoader|null
+	 */
 	public function getClassLoader(){
 		return $this->classLoader;
 	}
 
+	/**
+	 * @param \ClassLoader|null $loader
+	 *
+	 * @return void
+	 */
 	public function setClassLoader(\ClassLoader $loader = null){
 		$this->composerAutoloaderPath = \pocketmine\COMPOSER_AUTOLOADER_PATH;
 
@@ -55,6 +63,8 @@ abstract class Thread extends \Thread{
 	 * WARNING: This method MUST be called from any descendent threads' run() method to make autoloading usable.
 	 * If you do not do this, you will not be able to use new classes that were not loaded when the thread was started
 	 * (unless you are using a custom autoloader).
+	 *
+	 * @return void
 	 */
 	public function registerClassLoader(){
 		if($this->composerAutoloaderPath !== null){
@@ -65,6 +75,11 @@ abstract class Thread extends \Thread{
 		}
 	}
 
+	/**
+	 * @param int|null $options TODO: pthreads bug
+	 *
+	 * @return bool
+	 */
 	public function start(?int $options = \PTHREADS_INHERIT_ALL){
 		ThreadManager::getInstance()->add($this);
 
@@ -76,6 +91,8 @@ abstract class Thread extends \Thread{
 
 	/**
 	 * Stops the thread using the best way possible. Try to stop it yourself before calling this.
+	 *
+	 * @return void
 	 */
 	public function quit(){
 		$this->isKilled = true;
diff --git a/src/pocketmine/ThreadManager.php b/src/pocketmine/ThreadManager.php
index e90d598d6..b84f6509a 100644
--- a/src/pocketmine/ThreadManager.php
+++ b/src/pocketmine/ThreadManager.php
@@ -31,6 +31,9 @@ class ThreadManager extends \Volatile{
 	/** @var ThreadManager */
 	private static $instance = null;
 
+	/**
+	 * @return void
+	 */
 	public static function init(){
 		self::$instance = new ThreadManager();
 	}
@@ -44,6 +47,8 @@ class ThreadManager extends \Volatile{
 
 	/**
 	 * @param Worker|Thread $thread
+	 *
+	 * @return void
 	 */
 	public function add($thread){
 		if($thread instanceof Thread or $thread instanceof Worker){
@@ -53,6 +58,8 @@ class ThreadManager extends \Volatile{
 
 	/**
 	 * @param Worker|Thread $thread
+	 *
+	 * @return void
 	 */
 	public function remove($thread){
 		if($thread instanceof Thread or $thread instanceof Worker){
diff --git a/src/pocketmine/Worker.php b/src/pocketmine/Worker.php
index a8b843dba..ab5c81b50 100644
--- a/src/pocketmine/Worker.php
+++ b/src/pocketmine/Worker.php
@@ -36,10 +36,18 @@ abstract class Worker extends \Worker{
 	/** @var bool */
 	protected $isKilled = false;
 
+	/**
+	 * @return \ClassLoader|null
+	 */
 	public function getClassLoader(){
 		return $this->classLoader;
 	}
 
+	/**
+	 * @param \ClassLoader|null $loader
+	 *
+	 * @return void
+	 */
 	public function setClassLoader(\ClassLoader $loader = null){
 		$this->composerAutoloaderPath = \pocketmine\COMPOSER_AUTOLOADER_PATH;
 
@@ -55,6 +63,8 @@ abstract class Worker extends \Worker{
 	 * WARNING: This method MUST be called from any descendent threads' run() method to make autoloading usable.
 	 * If you do not do this, you will not be able to use new classes that were not loaded when the thread was started
 	 * (unless you are using a custom autoloader).
+	 *
+	 * @return void
 	 */
 	public function registerClassLoader(){
 		if($this->composerAutoloaderPath !== null){
@@ -65,6 +75,11 @@ abstract class Worker extends \Worker{
 		}
 	}
 
+	/**
+	 * @param int|null $options TODO: pthreads bug
+	 *
+	 * @return bool
+	 */
 	public function start(?int $options = \PTHREADS_INHERIT_ALL){
 		ThreadManager::getInstance()->add($this);
 
@@ -76,6 +91,8 @@ abstract class Worker extends \Worker{
 
 	/**
 	 * Stops the thread using the best way possible. Try to stop it yourself before calling this.
+	 *
+	 * @return void
 	 */
 	public function quit(){
 		$this->isKilled = true;