diff --git a/build/psalm-baseline.xml b/build/psalm-baseline.xml
index 937c2fe1687..c70ef72574c 100644
--- a/build/psalm-baseline.xml
+++ b/build/psalm-baseline.xml
@@ -2497,12 +2497,6 @@
     <ImplementedReturnTypeMismatch occurrences="1">
       <code>Color</code>
     </ImplementedReturnTypeMismatch>
-    <InvalidReturnStatement occurrences="1">
-      <code>$finalPalette[$this-&gt;hashToInt($hash, $steps * 3)]</code>
-    </InvalidReturnStatement>
-    <InvalidReturnType occurrences="1">
-      <code>Color</code>
-    </InvalidReturnType>
     <ParamNameMismatch occurrences="1">
       <code>$hash</code>
     </ParamNameMismatch>
diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 1edc39c52f2..646bd3acb5e 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -1548,6 +1548,8 @@ return array(
     'OC\\User\\Database' => $baseDir . '/lib/private/User/Database.php',
     'OC\\User\\DisplayNameCache' => $baseDir . '/lib/private/User/DisplayNameCache.php',
     'OC\\User\\LazyUser' => $baseDir . '/lib/private/User/LazyUser.php',
+    'OC\\User\\Listeners\\UserChangedListener' => $baseDir . '/lib/private/User/Listeners/UserChangedListener.php',
+    'OC\\User\\Listeners\\UserDeletedListener' => $baseDir . '/lib/private/User/Listeners/UserDeletedListener.php',
     'OC\\User\\LoginException' => $baseDir . '/lib/private/User/LoginException.php',
     'OC\\User\\Manager' => $baseDir . '/lib/private/User/Manager.php',
     'OC\\User\\NoUserException' => $baseDir . '/lib/private/User/NoUserException.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index 2efd6effc91..75d00eb32c7 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -1581,6 +1581,8 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OC\\User\\Database' => __DIR__ . '/../../..' . '/lib/private/User/Database.php',
         'OC\\User\\DisplayNameCache' => __DIR__ . '/../../..' . '/lib/private/User/DisplayNameCache.php',
         'OC\\User\\LazyUser' => __DIR__ . '/../../..' . '/lib/private/User/LazyUser.php',
+        'OC\\User\\Listeners\\UserChangedListener' => __DIR__ . '/../../..' . '/lib/private/User/Listeners/UserChangedListener.php',
+        'OC\\User\\Listeners\\UserDeletedListener' => __DIR__ . '/../../..' . '/lib/private/User/Listeners/UserDeletedListener.php',
         'OC\\User\\LoginException' => __DIR__ . '/../../..' . '/lib/private/User/LoginException.php',
         'OC\\User\\Manager' => __DIR__ . '/../../..' . '/lib/private/User/Manager.php',
         'OC\\User\\NoUserException' => __DIR__ . '/../../..' . '/lib/private/User/NoUserException.php',
diff --git a/lib/private/Avatar/Avatar.php b/lib/private/Avatar/Avatar.php
index f0e14ad8b2f..188e7378aff 100644
--- a/lib/private/Avatar/Avatar.php
+++ b/lib/private/Avatar/Avatar.php
@@ -46,9 +46,7 @@ use Psr\Log\LoggerInterface;
  * This class gets and sets users avatars.
  */
 abstract class Avatar implements IAvatar {
-
-	/** @var LoggerInterface  */
-	protected $logger;
+	protected LoggerInterface $logger;
 
 	/**
 	 * https://github.com/sebdesign/cap-height -- for 500px height
@@ -57,10 +55,8 @@ abstract class Avatar implements IAvatar {
 	 * (0.4 letter-to-total-height ratio, 500*0.4=200), so: 200/0.715 = 280px.
 	 * Since we start from the baseline (text-anchor) we need to
 	 * shift the y axis by 100px (half the caps height): 500/2+100=350
-	 *
-	 * @var string
 	 */
-	private $svgTemplate = '<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+	private string $svgTemplate = '<?xml version="1.0" encoding="UTF-8" standalone="no"?>
 		<svg width="{size}" height="{size}" version="1.1" viewBox="0 0 500 500" xmlns="http://www.w3.org/2000/svg">
 			<rect width="100%" height="100%" fill="#{fill}"></rect>
 			<text x="50%" y="350" style="font-weight:normal;font-size:280px;font-family:\'Noto Sans\';text-anchor:middle;fill:#fff">{letter}</text>
@@ -72,15 +68,11 @@ abstract class Avatar implements IAvatar {
 
 	/**
 	 * Returns the user display name.
-	 *
-	 * @return string
 	 */
 	abstract public function getDisplayName(): string;
 
 	/**
 	 * Returns the first letter of the display name, or "?" if no name given.
-	 *
-	 * @return string
 	 */
 	private function getAvatarText(): string {
 		$displayName = $this->getDisplayName();
@@ -96,9 +88,7 @@ abstract class Avatar implements IAvatar {
 	/**
 	 * @inheritdoc
 	 */
-	public function get($size = 64) {
-		$size = (int) $size;
-
+	public function get(int $size = 64) {
 		try {
 			$file = $this->getFile($size);
 		} catch (NotFoundException $e) {
@@ -158,12 +148,8 @@ abstract class Avatar implements IAvatar {
 
 	/**
 	 * Generate png avatar with GD
-	 *
-	 * @param string $userDisplayName
-	 * @param int $size
-	 * @return string
 	 */
-	protected function generateAvatar($userDisplayName, $size) {
+	protected function generateAvatar(string $userDisplayName, int $size): string {
 		$text = $this->getAvatarText();
 		$backgroundColor = $this->avatarBackgroundColor($userDisplayName);
 
@@ -209,7 +195,7 @@ abstract class Avatar implements IAvatar {
 		string $text,
 		string $font,
 		int $size,
-		$angle = 0
+		int $angle = 0
 	): array {
 		// Image width & height
 		$xi = imagesx($image);
@@ -231,11 +217,11 @@ abstract class Avatar implements IAvatar {
 
 	/**
 	 * Calculate steps between two Colors
-	 * @param object Color $steps start color
-	 * @param object Color $ends end color
-	 * @return array [r,g,b] steps for each color to go from $steps to $ends
+	 * @param int $steps start color
+	 * @param Color[] $ends end color
+	 * @return array{0: int, 1: int, 2: int} [r,g,b] steps for each color to go from $steps to $ends
 	 */
-	private function stepCalc($steps, $ends) {
+	private function stepCalc(int $steps, array $ends): array {
 		$step = [];
 		$step[0] = ($ends[1]->r - $ends[0]->r) / $steps;
 		$step[1] = ($ends[1]->g - $ends[0]->g) / $steps;
@@ -244,12 +230,11 @@ abstract class Avatar implements IAvatar {
 	}
 
 	/**
-	 * Convert a string to an integer evenly
-	 * @param string $hash the text to parse
-	 * @param int $maximum the maximum range
-	 * @return int[] between 0 and $maximum
+	 * Mix two colors
+	 *
+	 * @return Color[]
 	 */
-	private function mixPalette($steps, $color1, $color2) {
+	private function mixPalette($steps, Color $color1, Color $color2) {
 		$palette = [$color1];
 		$step = $this->stepCalc($steps, [$color1, $color2]);
 		for ($i = 1; $i < $steps; $i++) {
@@ -267,7 +252,7 @@ abstract class Avatar implements IAvatar {
 	 * @param int $maximum the maximum range
 	 * @return int between 0 and $maximum
 	 */
-	private function hashToInt($hash, $maximum) {
+	private function hashToInt(string $hash, int $maximum): int {
 		$final = 0;
 		$result = [];
 
@@ -285,10 +270,9 @@ abstract class Avatar implements IAvatar {
 	}
 
 	/**
-	 * @param string $hash
 	 * @return Color Object containting r g b int in the range [0, 255]
 	 */
-	public function avatarBackgroundColor(string $hash) {
+	public function avatarBackgroundColor(string $hash): Color {
 		// Normalize hash
 		$hash = strtolower($hash);
 
diff --git a/lib/private/Avatar/GuestAvatar.php b/lib/private/Avatar/GuestAvatar.php
index f0297b3a93c..f3dde0840e9 100644
--- a/lib/private/Avatar/GuestAvatar.php
+++ b/lib/private/Avatar/GuestAvatar.php
@@ -26,6 +26,7 @@ declare(strict_types=1);
  */
 namespace OC\Avatar;
 
+use OCP\Files\SimpleFS\ISimpleFile;
 use OCP\Files\SimpleFS\InMemoryFile;
 use Psr\Log\LoggerInterface;
 
@@ -35,16 +36,13 @@ use Psr\Log\LoggerInterface;
 class GuestAvatar extends Avatar {
 	/**
 	 * Holds the guest user display name.
-	 *
-	 * @var string
 	 */
-	private $userDisplayName;
+	private string $userDisplayName;
 
 	/**
 	 * GuestAvatar constructor.
 	 *
 	 * @param string $userDisplayName The guest user display name
-	 * @param LoggerInterface $logger The logger
 	 */
 	public function __construct(string $userDisplayName, LoggerInterface $logger) {
 		parent::__construct($logger);
@@ -53,17 +51,13 @@ class GuestAvatar extends Avatar {
 
 	/**
 	 * Tests if the user has an avatar.
-	 *
-	 * @return true Guests always have an avatar.
 	 */
-	public function exists() {
-		return true;
+	public function exists(): bool {
+		return true; // Guests always have an avatar.
 	}
 
 	/**
 	 * Returns the guest user display name.
-	 *
-	 * @return string
 	 */
 	public function getDisplayName(): string {
 		return $this->userDisplayName;
@@ -75,24 +69,21 @@ class GuestAvatar extends Avatar {
 	 * @param \OCP\IImage|resource|string $data
 	 * @return void
 	 */
-	public function set($data) {
+	public function set($data): void {
 		// unimplemented for guest user avatars
 	}
 
 	/**
 	 * Removing avatars isn't implemented for guests.
 	 */
-	public function remove() {
+	public function remove(bool $silent = false): void {
 		// unimplemented for guest user avatars
 	}
 
 	/**
 	 * Generates an avatar for the guest.
-	 *
-	 * @param int $size The desired image size.
-	 * @return InMemoryFile
 	 */
-	public function getFile($size) {
+	public function getFile(int $size): ISimpleFile {
 		$avatar = $this->generateAvatar($this->userDisplayName, $size);
 		return new InMemoryFile('avatar.png', $avatar);
 	}
@@ -103,9 +94,8 @@ class GuestAvatar extends Avatar {
 	 * @param string $feature The changed feature
 	 * @param mixed $oldValue The previous value
 	 * @param mixed $newValue The new value
-	 * @return void
 	 */
-	public function userChanged($feature, $oldValue, $newValue) {
+	public function userChanged(string $feature, $oldValue, $newValue): void {
 		if ($feature === 'displayName') {
 			$this->userDisplayName = $newValue;
 		}
@@ -113,8 +103,6 @@ class GuestAvatar extends Avatar {
 
 	/**
 	 * Guests don't have custom avatars.
-	 *
-	 * @return bool
 	 */
 	public function isCustomAvatar(): bool {
 		return false;
diff --git a/lib/private/Avatar/PlaceholderAvatar.php b/lib/private/Avatar/PlaceholderAvatar.php
index df7a490cbe4..504e5c1457d 100644
--- a/lib/private/Avatar/PlaceholderAvatar.php
+++ b/lib/private/Avatar/PlaceholderAvatar.php
@@ -44,11 +44,8 @@ use Psr\Log\LoggerInterface;
  * for faster retrieval, unlike the GuestAvatar.
  */
 class PlaceholderAvatar extends Avatar {
-	/** @var ISimpleFolder */
-	private $folder;
-
-	/** @var User */
-	private $user;
+	private ISimpleFolder $folder;
+	private User $user;
 
 	/**
 	 * UserAvatar constructor.
@@ -71,10 +68,8 @@ class PlaceholderAvatar extends Avatar {
 
 	/**
 	 * Check if an avatar exists for the user
-	 *
-	 * @return bool
 	 */
-	public function exists() {
+	public function exists(): bool {
 		return true;
 	}
 
@@ -87,14 +82,14 @@ class PlaceholderAvatar extends Avatar {
 	 * @throws NotSquareException if the image is not square
 	 * @return void
 	 */
-	public function set($data) {
+	public function set($data): void {
 		// unimplemented for placeholder avatars
 	}
 
 	/**
 	 * Removes the users avatar.
 	 */
-	public function remove(bool $silent = false) {
+	public function remove(bool $silent = false): void {
 		$avatars = $this->folder->getDirectoryListing();
 
 		foreach ($avatars as $avatar) {
@@ -113,9 +108,7 @@ class PlaceholderAvatar extends Avatar {
 	 * @throws \OCP\Files\NotPermittedException
 	 * @throws \OCP\PreConditionNotMetException
 	 */
-	public function getFile($size) {
-		$size = (int) $size;
-
+	public function getFile(int $size): ISimpleFile {
 		$ext = 'png';
 
 		if ($size === -1) {
@@ -149,8 +142,6 @@ class PlaceholderAvatar extends Avatar {
 
 	/**
 	 * Returns the user display name.
-	 *
-	 * @return string
 	 */
 	public function getDisplayName(): string {
 		return $this->user->getDisplayName();
@@ -165,14 +156,12 @@ class PlaceholderAvatar extends Avatar {
 	 * @throws NotPermittedException
 	 * @throws \OCP\PreConditionNotMetException
 	 */
-	public function userChanged($feature, $oldValue, $newValue) {
+	public function userChanged(string $feature, $oldValue, $newValue): void {
 		$this->remove();
 	}
 
 	/**
 	 * Check if the avatar of a user is a custom uploaded one
-	 *
-	 * @return bool
 	 */
 	public function isCustomAvatar(): bool {
 		return false;
diff --git a/lib/private/Avatar/UserAvatar.php b/lib/private/Avatar/UserAvatar.php
index 6cca5a1c355..191a6ebfff4 100644
--- a/lib/private/Avatar/UserAvatar.php
+++ b/lib/private/Avatar/UserAvatar.php
@@ -44,17 +44,10 @@ use Psr\Log\LoggerInterface;
  * This class represents a registered user's avatar.
  */
 class UserAvatar extends Avatar {
-	/** @var IConfig */
-	private $config;
-
-	/** @var ISimpleFolder */
-	private $folder;
-
-	/** @var IL10N */
-	private $l;
-
-	/** @var User */
-	private $user;
+	private IConfig $config;
+	private ISimpleFolder $folder;
+	private IL10N $l;
+	private User $user;
 
 	/**
 	 * UserAvatar constructor.
@@ -68,7 +61,7 @@ class UserAvatar extends Avatar {
 	public function __construct(
 		ISimpleFolder $folder,
 		IL10N $l,
-		$user,
+		User $user,
 		LoggerInterface $logger,
 		IConfig $config) {
 		parent::__construct($logger);
@@ -80,10 +73,8 @@ class UserAvatar extends Avatar {
 
 	/**
 	 * Check if an avatar exists for the user
-	 *
-	 * @return bool
 	 */
-	public function exists() {
+	public function exists(): bool {
 		return $this->folder->fileExists('avatar.jpg') || $this->folder->fileExists('avatar.png');
 	}
 
@@ -96,7 +87,7 @@ class UserAvatar extends Avatar {
 	 * @throws NotSquareException if the image is not square
 	 * @return void
 	 */
-	public function set($data) {
+	public function set($data): void {
 		$img = $this->getAvatarImage($data);
 		$data = $img->data();
 
@@ -124,7 +115,7 @@ class UserAvatar extends Avatar {
 	 * @param IImage|resource|string|\GdImage $data An image object, imagedata or path to the avatar
 	 * @return IImage
 	 */
-	private function getAvatarImage($data) {
+	private function getAvatarImage($data): IImage {
 		if ($data instanceof IImage) {
 			return $data;
 		}
@@ -156,11 +147,8 @@ class UserAvatar extends Avatar {
 
 	/**
 	 * Returns the avatar image type.
-	 *
-	 * @param IImage $avatar
-	 * @return string
 	 */
-	private function getAvatarImageType(IImage $avatar) {
+	private function getAvatarImageType(IImage $avatar): string {
 		$type = substr($avatar->mimeType(), -3);
 		if ($type === 'peg') {
 			$type = 'jpg';
@@ -179,7 +167,7 @@ class UserAvatar extends Avatar {
 	 * @throws \Exception if the provided image is not valid
 	 * @throws NotSquareException if the image is not square
 	 */
-	private function validateAvatar(IImage $avatar) {
+	private function validateAvatar(IImage $avatar): void {
 		$type = $this->getAvatarImageType($avatar);
 
 		if ($type !== 'jpg' && $type !== 'png') {
@@ -197,11 +185,10 @@ class UserAvatar extends Avatar {
 
 	/**
 	 * Removes the users avatar.
-	 * @return void
 	 * @throws \OCP\Files\NotPermittedException
 	 * @throws \OCP\PreConditionNotMetException
 	 */
-	public function remove(bool $silent = false) {
+	public function remove(bool $silent = false): void {
 		$avatars = $this->folder->getDirectoryListing();
 
 		$this->config->setUserValue($this->user->getUID(), 'avatar', 'version',
@@ -219,10 +206,9 @@ class UserAvatar extends Avatar {
 	/**
 	 * Get the extension of the avatar. If there is no avatar throw Exception
 	 *
-	 * @return string
 	 * @throws NotFoundException
 	 */
-	private function getExtension() {
+	private function getExtension(): string {
 		if ($this->folder->fileExists('avatar.jpg')) {
 			return 'jpg';
 		} elseif ($this->folder->fileExists('avatar.png')) {
@@ -242,9 +228,7 @@ class UserAvatar extends Avatar {
 	 * @throws \OCP\Files\NotPermittedException
 	 * @throws \OCP\PreConditionNotMetException
 	 */
-	public function getFile($size) {
-		$size = (int) $size;
-
+	public function getFile(int $size): ISimpleFile {
 		try {
 			$ext = $this->getExtension();
 		} catch (NotFoundException $e) {
@@ -304,8 +288,6 @@ class UserAvatar extends Avatar {
 
 	/**
 	 * Returns the user display name.
-	 *
-	 * @return string
 	 */
 	public function getDisplayName(): string {
 		return $this->user->getDisplayName();
@@ -320,7 +302,7 @@ class UserAvatar extends Avatar {
 	 * @throws NotPermittedException
 	 * @throws \OCP\PreConditionNotMetException
 	 */
-	public function userChanged($feature, $oldValue, $newValue) {
+	public function userChanged(string $feature, $oldValue, $newValue): void {
 		// If the avatar is not generated (so an uploaded image) we skip this
 		if (!$this->folder->fileExists('generated')) {
 			return;
@@ -331,8 +313,6 @@ class UserAvatar extends Avatar {
 
 	/**
 	 * Check if the avatar of a user is a custom uploaded one
-	 *
-	 * @return bool
 	 */
 	public function isCustomAvatar(): bool {
 		return $this->config->getUserValue($this->user->getUID(), 'avatar', 'generated', 'false') !== 'true';
diff --git a/lib/private/Server.php b/lib/private/Server.php
index 6e6fa430489..bcbb6ef6b00 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -151,6 +151,8 @@ use OC\SystemTag\ManagerFactory as SystemTagManagerFactory;
 use OC\Tagging\TagMapper;
 use OC\Talk\Broker;
 use OC\Template\JSCombiner;
+use OC\User\Listeners\UserChangedListener;
+use OC\User\Listeners\UserDeletedListener;
 use OCA\Theming\ImageManager;
 use OCA\Theming\ThemingDefaults;
 use OCA\Theming\Util;
@@ -180,7 +182,6 @@ use OCP\Files\IMimeTypeLoader;
 use OCP\Files\IRootFolder;
 use OCP\Files\Lock\ILockManager;
 use OCP\Files\Mount\IMountManager;
-use OCP\Files\NotFoundException;
 use OCP\Files\Storage\IStorageFactory;
 use OCP\Files\Template\ITemplateManager;
 use OCP\FullTextSearch\IFullTextSearchManager;
@@ -217,7 +218,6 @@ use OCP\ISession;
 use OCP\ITagManager;
 use OCP\ITempManager;
 use OCP\IURLGenerator;
-use OCP\IUser;
 use OCP\IUserManager;
 use OCP\IUserSession;
 use OCP\L10N\IFactory;
@@ -249,6 +249,7 @@ use OCP\User\Events\BeforeUserLoggedOutEvent;
 use OCP\User\Events\PasswordUpdatedEvent;
 use OCP\User\Events\PostLoginEvent;
 use OCP\User\Events\UserChangedEvent;
+use OCP\User\Events\UserDeletedEvent;
 use OCP\User\Events\UserLoggedInEvent;
 use OCP\User\Events\UserLoggedInWithCookieEvent;
 use OCP\User\Events\UserLoggedOutEvent;
@@ -1473,52 +1474,13 @@ class Server extends ServerContainer implements IServerContainer {
 		return $this->get(\OC\Calendar\Room\Manager::class);
 	}
 
-	private function connectDispatcher() {
-		$dispatcher = $this->get(SymfonyAdapter::class);
-
-		// Delete avatar on user deletion
-		$dispatcher->addListener('OCP\IUser::preDelete', function (GenericEvent $e) {
-			$logger = $this->get(LoggerInterface::class);
-			$manager = $this->getAvatarManager();
-			/** @var IUser $user */
-			$user = $e->getSubject();
-
-			try {
-				$avatar = $manager->getAvatar($user->getUID());
-				$avatar->remove();
-			} catch (NotFoundException $e) {
-				// no avatar to remove
-			} catch (\Exception $e) {
-				// Ignore exceptions
-				$logger->info('Could not cleanup avatar of ' . $user->getUID());
-			}
-		});
-
-		$dispatcher->addListener('OCP\IUser::changeUser', function (GenericEvent $e) {
-			$manager = $this->getAvatarManager();
-			/** @var IUser $user */
-			$user = $e->getSubject();
-			$feature = $e->getArgument('feature');
-			$oldValue = $e->getArgument('oldValue');
-			$value = $e->getArgument('value');
-
-			// We only change the avatar on display name changes
-			if ($feature !== 'displayName') {
-				return;
-			}
-
-			try {
-				$avatar = $manager->getAvatar($user->getUID());
-				$avatar->userChanged($feature, $oldValue, $value);
-			} catch (NotFoundException $e) {
-				// no avatar to remove
-			}
-		});
-
-		/** @var IEventDispatcher $eventDispatched */
-		$eventDispatched = $this->get(IEventDispatcher::class);
-		$eventDispatched->addServiceListener(LoginFailed::class, LoginFailedListener::class);
-		$eventDispatched->addServiceListener(PostLoginEvent::class, UserLoggedInListener::class);
+	private function connectDispatcher(): void {
+		/** @var IEventDispatcher $eventDispatcher */
+		$eventDispatcher = $this->get(IEventDispatcher::class);
+		$eventDispatcher->addServiceListener(LoginFailed::class, LoginFailedListener::class);
+		$eventDispatcher->addServiceListener(PostLoginEvent::class, UserLoggedInListener::class);
+		$eventDispatcher->addServiceListener(UserChangedEvent::class, UserChangedListener::class);
+		$eventDispatcher->addServiceListener(UserDeletedEvent::class, UserDeletedListener::class);
 	}
 
 	/**
diff --git a/lib/private/User/Listeners/UserChangedListener.php b/lib/private/User/Listeners/UserChangedListener.php
new file mode 100644
index 00000000000..f3c7468460a
--- /dev/null
+++ b/lib/private/User/Listeners/UserChangedListener.php
@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2022 Carl Schwan <carl@carlschwan.eu>
+ *
+ * @license AGPL-3.0-or-later
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OC\User\Listeners;
+
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\User\Events\UserChangedEvent;
+use OCP\Files\NotFoundException;
+use OCP\IAvatarManager;
+
+/**
+ * @template-implements IEventListener<\OCP\User\Events\UserChangedEvent>
+ */
+class UserChangedListener implements IEventListener {
+	private IAvatarManager $avatarManager;
+
+	public function __construct(IAvatarManager $avatarManager) {
+		$this->avatarManager = $avatarManager;
+	}
+
+	public function handle(Event $event): void {
+		if (!($event instanceof UserChangedEvent)) {
+			return;
+		}
+		
+		$user = $event->getUser();
+		$feature = $event->getFeature();
+		$oldValue = $event->getOldValue();
+		$value = $event->getValue();
+
+		// We only change the avatar on display name changes
+		if ($feature === 'displayName') {
+			try {
+				$avatar = $this->avatarManager->getAvatar($user->getUID());
+				$avatar->userChanged($feature, $oldValue, $value);
+			} catch (NotFoundException $e) {
+				// no avatar to remove
+			}
+		}
+	}
+}
diff --git a/lib/private/User/Listeners/UserDeletedListener.php b/lib/private/User/Listeners/UserDeletedListener.php
new file mode 100644
index 00000000000..a8ad56d97ab
--- /dev/null
+++ b/lib/private/User/Listeners/UserDeletedListener.php
@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2022 Carl Schwan <carl@carlschwan.eu>
+ *
+ * @license AGPL-3.0-or-later
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OC\User\Listeners;
+
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\User\Events\UserDeletedEvent;
+use OCP\Files\NotFoundException;
+use OCP\IAvatarManager;
+use Psr\Log\LoggerInterface;
+
+/**
+ * @template-implements IEventListener<\OCP\User\Events\UserDeletedEvent>
+ */
+class UserDeletedListener implements IEventListener {
+	private IAvatarManager $avatarManager;
+	private LoggerInterface $logger;
+
+	public function __construct(LoggerInterface $logger, IAvatarManager $avatarManager) {
+		$this->avatarManager = $avatarManager;
+		$this->logger = $logger;
+	}
+
+	public function handle(Event $event): void {
+		if (!($event instanceof UserDeletedEvent)) {
+			return;
+		}
+		
+		$user = $event->getUser();
+
+		// Delete avatar on user deletion
+		try {
+			$avatar = $this->avatarManager->getAvatar($user->getUID());
+			$avatar->remove();
+		} catch (NotFoundException $e) {
+			// no avatar to remove
+		} catch (\Exception $e) {
+			// Ignore exceptions
+			$this->logger->info('Could not cleanup avatar of ' . $user->getUID());
+		}
+	}
+}
diff --git a/lib/public/IAvatar.php b/lib/public/IAvatar.php
index 218ef258250..e4a9ce5dcc1 100644
--- a/lib/public/IAvatar.php
+++ b/lib/public/IAvatar.php
@@ -36,66 +36,71 @@ use OCP\Files\SimpleFS\ISimpleFile;
 interface IAvatar {
 
 	/**
-	 * get the users avatar
+	 * Get the users avatar
+	 *
 	 * @param int $size size in px of the avatar, avatars are square, defaults to 64, -1 can be used to not scale the image
 	 * @return false|\OCP\IImage containing the avatar or false if there's no image
 	 * @since 6.0.0 - size of -1 was added in 9.0.0
 	 */
-	public function get($size = 64);
+	public function get(int $size = 64);
 
 	/**
 	 * Check if an avatar exists for the user
 	 *
-	 * @return bool
 	 * @since 8.1.0
 	 */
-	public function exists();
+	public function exists(): bool;
 
 	/**
 	 * Check if the avatar of a user is a custom uploaded one
 	 *
-	 * @return bool
 	 * @since 14.0.0
 	 */
 	public function isCustomAvatar(): bool;
 
 	/**
-	 * sets the users avatar
+	 * Sets the users avatar
+	 *
 	 * @param \OCP\IImage|resource|string $data An image object, imagedata or path to set a new avatar
 	 * @throws \Exception if the provided file is not a jpg or png image
 	 * @throws \Exception if the provided image is not valid
 	 * @throws \OC\NotSquareException if the image is not square
-	 * @return void
 	 * @since 6.0.0
 	 */
-	public function set($data);
+	public function set($data): void;
 
 	/**
-	 * remove the users avatar
-	 * @return void
+	 * Remove the user's avatar
+	 *
+	 * @param bool $silent Whether removing the avatar should trigger a change
 	 * @since 6.0.0
 	 */
-	public function remove();
+	public function remove(bool $silent = false): void;
 
 	/**
 	 * Get the file of the avatar
-	 * @param int $size -1 can be used to not scale the image
-	 * @return ISimpleFile
+	 *
+	 * @param int $size The desired image size. -1 can be used to not scale the image
 	 * @throws NotFoundException
 	 * @since 9.0.0
 	 */
-	public function getFile($size);
+	public function getFile(int $size): ISimpleFile;
 
 	/**
-	 * @param string $text
+	 * Get the avatar background color
+	 *
 	 * @return Color Object containting r g b int in the range [0, 255]
 	 * @since 14.0.0
 	 */
 	public function avatarBackgroundColor(string $text);
 
 	/**
-	 * Handle a changed user
+	 * Updates the display name if changed.
+	 *
+	 * @param string $feature The changed feature
+	 * @param mixed $oldValue The previous value
+	 * @param mixed $newValue The new value
 	 * @since 13.0.0
 	 */
-	public function userChanged($feature, $oldValue, $newValue);
+	public function userChanged(string $feature, $oldValue, $newValue): void;
 }
diff --git a/lib/public/User/Events/UserChangedEvent.php b/lib/public/User/Events/UserChangedEvent.php
index 3a40f8c3f11..f48dd3914e6 100644
--- a/lib/public/User/Events/UserChangedEvent.php
+++ b/lib/public/User/Events/UserChangedEvent.php
@@ -32,16 +32,10 @@ use OCP\IUser;
  * @since 18.0.0
  */
 class UserChangedEvent extends Event {
-
-	/** @var IUser */
-	private $user;
-
-	/** @var string */
-	private $feature;
-
+	private IUser $user;
+	private string $feature;
 	/** @var mixed */
 	private $value;
-
 	/** @var mixed */
 	private $oldValue;
 
diff --git a/tests/lib/Avatar/AvatarManagerTest.php b/tests/lib/Avatar/AvatarManagerTest.php
index ae9c0e1671f..ce9475a4600 100644
--- a/tests/lib/Avatar/AvatarManagerTest.php
+++ b/tests/lib/Avatar/AvatarManagerTest.php
@@ -101,7 +101,7 @@ class AvatarManagerTest extends \Test\TestCase {
 	}
 
 	public function testGetAvatarForSelf() {
-		$user = $this->createMock(IUser::class);
+		$user = $this->createMock(\OC\User\User::class);
 		$user
 			->expects($this->any())
 			->method('getUID')
@@ -151,7 +151,7 @@ class AvatarManagerTest extends \Test\TestCase {
 	}
 
 	public function testGetAvatarValidUserDifferentCasing() {
-		$user = $this->createMock(IUser::class);
+		$user = $this->createMock(\OC\User\User::class);
 		$this->userManager->expects($this->once())
 			->method('get')
 			->with('vaLid-USER')
@@ -225,7 +225,7 @@ class AvatarManagerTest extends \Test\TestCase {
 			->method('getUser')
 			->willReturn($requestingUser);
 
-		$user = $this->createMock(IUser::class);
+		$user = $this->createMock(\OC\User\User::class);
 		$user
 			->expects($this->once())
 			->method('getUID')
diff --git a/tests/lib/Avatar/UserAvatarTest.php b/tests/lib/Avatar/UserAvatarTest.php
index dd5f25163f2..bd45a819760 100644
--- a/tests/lib/Avatar/UserAvatarTest.php
+++ b/tests/lib/Avatar/UserAvatarTest.php
@@ -57,7 +57,7 @@ class UserAvatarTest extends \Test\TestCase {
 			->willReturn($file);
 
 		$this->folder->method('getFile')
-			->willReturnCallback(function ($path) {
+			->willReturnCallback(function (string $path) {
 				if ($path === 'avatar.64.png') {
 					throw new NotFoundException();
 				}
@@ -96,7 +96,7 @@ class UserAvatarTest extends \Test\TestCase {
 		$expected = new \OC_Image();
 		$expected->loadFromFile(\OC::$SERVERROOT . '/tests/data/testavatar.png');
 
-		$file = $this->createMock(File::class);
+		$file = $this->createMock(ISimpleFile::class);
 		$file->method('getContent')->willReturn($expected->data());
 		$this->folder->method('getFile')->with('avatar.128.jpg')->willReturn($file);
 
@@ -112,7 +112,7 @@ class UserAvatarTest extends \Test\TestCase {
 		$expected = new \OC_Image();
 		$expected->loadFromFile(\OC::$SERVERROOT . '/tests/data/testavatar.png');
 
-		$file = $this->createMock(File::class);
+		$file = $this->createMock(ISimpleFile::class);
 		$file->method('getContent')->willReturn($expected->data());
 		$this->folder->method('getFile')->with('avatar.jpg')->willReturn($file);
 
@@ -132,7 +132,7 @@ class UserAvatarTest extends \Test\TestCase {
 		$expected2->loadFromFile(\OC::$SERVERROOT . '/tests/data/testavatar.png');
 		$expected2->resize(32);
 
-		$file = $this->createMock(File::class);
+		$file = $this->createMock(ISimpleFile::class);
 		$file->method('getContent')->willReturn($expected->data());
 
 		$this->folder->method('getFile')
@@ -146,7 +146,7 @@ class UserAvatarTest extends \Test\TestCase {
 				}
 			);
 
-		$newFile = $this->createMock(File::class);
+		$newFile = $this->createMock(ISimpleFile::class);
 		$newFile->expects($this->once())
 			->method('putContent')
 			->with($expected2->data());