diff --git a/CHANGELOG.md b/CHANGELOG.md
index e0925a381..1bace3861 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 - Release 2.4.4 🦩 ([belomaxorka](https://github.com/belomaxorka))
 - CWE-502 Fixed: Deserialization of untrusted data ([belomaxorka](https://github.com/belomaxorka))
 - Create tech stack docs (techstack.yml and techstack.md) [\#1521](https://github.com/torrentpier/torrentpier/pull/1521), [\#1522](https://github.com/torrentpier/torrentpier/pull/1522) ([belomaxorka](https://github.com/belomaxorka))
+- Added integration with MonsterID 🎇 [\#1546](https://github.com/torrentpier/torrentpier/pull/1546) ([belomaxorka](https://github.com/belomaxorka))
 - Added ability to reset ratio [\#1545](https://github.com/torrentpier/torrentpier/pull/1545) ([belomaxorka](https://github.com/belomaxorka))
 - Fixed broken "Disable Board" function [\#1529](https://github.com/torrentpier/torrentpier/pull/1529) ([belomaxorka](https://github.com/belomaxorka))
 - Fixed seed bonus accrual [\#1518](https://github.com/torrentpier/torrentpier/pull/1518) ([belomaxorka](https://github.com/belomaxorka))
diff --git a/composer.json b/composer.json
index 61f96ee7b..e375574e0 100644
--- a/composer.json
+++ b/composer.json
@@ -38,6 +38,7 @@
   "require": {
     "php": "^8.1",
     "arokettu/bencode": "^4.1.0",
+    "arokettu/monsterid": "^4.0",
     "arokettu/torrent-file": "^5.2.1",
     "bugsnag/bugsnag": "^v3.29.1",
     "claviska/simpleimage": "^4.0",
@@ -63,7 +64,10 @@
   },
   "config": {
     "sort-packages": true,
-    "optimize-autoloader": true
+    "optimize-autoloader": true,
+    "allow-plugins": {
+      "php-http/discovery": true
+    }
   },
   "minimum-stability": "stable",
   "prefer-stable": true
diff --git a/composer.lock b/composer.lock
index 35e80f3b5..3a3d65f14 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "0262bbf45b724f07d7e21875b5eafa44",
+    "content-hash": "4978862c1744c10fc0986a0ef31f0e81",
     "packages": [
         {
             "name": "arokettu/bencode",
@@ -137,6 +137,143 @@
             },
             "time": "2023-08-28T12:32:54+00:00"
         },
+        {
+            "name": "arokettu/monsterid",
+            "version": "4.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/arokettu/monsterid.git",
+                "reference": "f9c59ae43b8b5a3e4361b65eb240f1a62562f5e1"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/arokettu/monsterid/zipball/f9c59ae43b8b5a3e4361b65eb240f1a62562f5e1",
+                "reference": "f9c59ae43b8b5a3e4361b65eb240f1a62562f5e1",
+                "shasum": ""
+            },
+            "require": {
+                "arokettu/is-resource": "^1.0",
+                "arokettu/random-polyfill": "^1.0.1",
+                "ext-gd": "*",
+                "php": "^8.0",
+                "php-http/discovery": "^1.19",
+                "psr/http-factory": "^1.0"
+            },
+            "require-dev": {
+                "arokettu/random-polyfill": ">= 1.0.1 < 1.99",
+                "httpsoft/http-message": "^1.1",
+                "phpunit/phpunit": ">= 7.0 < 10",
+                "psy/psysh": "*",
+                "sandfox.dev/code-standard": "^1.2023.12.09",
+                "squizlabs/php_codesniffer": "*",
+                "vimeo/psalm": "^5.4"
+            },
+            "type": "library",
+            "autoload": {
+                "files": [
+                    "src/functions.php"
+                ],
+                "psr-4": {
+                    "Arokettu\\MonsterID\\": "src/classes"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Andreas Gohr",
+                    "homepage": "https://www.splitbrain.org/",
+                    "role": "developer"
+                },
+                {
+                    "name": "Anton Smirnov",
+                    "email": "sandfox@sandfox.me",
+                    "homepage": "https://sandfox.me/",
+                    "role": "maintainer"
+                }
+            ],
+            "description": "MonsterID is a method to generate a unique monster image based upon a certain identifier (IP address, email address, whatever). It can be used to automatically provide personal avatar images in blog comments or other community services.",
+            "homepage": "https://sandfox.dev/php/monsterid.html",
+            "keywords": [
+                "avatar",
+                "monsterid"
+            ],
+            "support": {
+                "docs": "https://monsterid.readthedocs.io/",
+                "issues": "https://gitlab.com/sandfox/monsterid/-/issues",
+                "source": "https://gitlab.com/sandfox/monsterid"
+            },
+            "time": "2024-01-03T01:03:52+00:00"
+        },
+        {
+            "name": "arokettu/random-polyfill",
+            "version": "1.0.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/arokettu/php-random-polyfill.git",
+                "reference": "1c36416a2b507d5aa6c0a6d7f7b8aa2c539f8361"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/arokettu/php-random-polyfill/zipball/1c36416a2b507d5aa6c0a6d7f7b8aa2c539f8361",
+                "reference": "1c36416a2b507d5aa6c0a6d7f7b8aa2c539f8361",
+                "shasum": ""
+            },
+            "require": {
+                "arokettu/unsigned": "^1.2.1",
+                "php": "^7.1 | ^8.0",
+                "symfony/polyfill-php80": "^1.22",
+                "symfony/polyfill-php81": "^1.22",
+                "symfony/polyfill-php82": "^1.27"
+            },
+            "provide": {
+                "ext-random": "8.2.0"
+            },
+            "require-dev": {
+                "phpunit/phpunit": "^7.5 | ^8.5 | 9.5.*",
+                "psy/psysh": "*",
+                "sandfox.dev/code-standard": "^1",
+                "squizlabs/php_codesniffer": "*",
+                "vimeo/psalm": "^4.24"
+            },
+            "suggest": {
+                "ext-gmp": "For significantly faster calculation"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-0": {
+                    "Random\\": "src",
+                    "Arokettu\\Random\\": "src"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause"
+            ],
+            "authors": [
+                {
+                    "name": "Anton Smirnov",
+                    "email": "sandfox@sandfox.me",
+                    "homepage": "https://sandfox.me/",
+                    "role": "developer"
+                }
+            ],
+            "description": "Random Extension Polyfill for PHP",
+            "homepage": "https://sandfox.dev/php/random-polyfill.html",
+            "keywords": [
+                "polyfill",
+                "random"
+            ],
+            "support": {
+                "chat": "https://gitter.im/arokettu/community",
+                "docs": "https://php-random-polyfill.readthedocs.io/",
+                "issues": "https://github.com/arokettu/php-random-polyfill/issues",
+                "source": "https://github.com/arokettu/php-random-polyfill"
+            },
+            "time": "2023-09-07T13:01:52+00:00"
+        },
         {
             "name": "arokettu/system-clock",
             "version": "2.0.0",
@@ -271,6 +408,61 @@
             },
             "time": "2024-01-31T20:45:07+00:00"
         },
+        {
+            "name": "arokettu/unsigned",
+            "version": "1.3.5",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/arokettu/unsigned.git",
+                "reference": "559dd1247fb4bbc9d70a6ff8581d8e9fd742e096"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/arokettu/unsigned/zipball/559dd1247fb4bbc9d70a6ff8581d8e9fd742e096",
+                "reference": "559dd1247fb4bbc9d70a6ff8581d8e9fd742e096",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.0 | ^8.0"
+            },
+            "require-dev": {
+                "phpunit/phpunit": ">= 6.5 <10",
+                "psy/psysh": "*",
+                "sandfox.dev/code-standard": "^1.2023.12.09",
+                "squizlabs/php_codesniffer": "*"
+            },
+            "type": "library",
+            "autoload": {
+                "files": [
+                    "src/lib.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-2-Clause"
+            ],
+            "authors": [
+                {
+                    "name": "Anton Smirnov",
+                    "email": "sandfox@sandfox.me",
+                    "homepage": "https://sandfox.me/",
+                    "role": "developer"
+                }
+            ],
+            "description": "Fixed length unsigned arithmetic emulation",
+            "homepage": "https://sandfox.dev/php/unsigned.html",
+            "keywords": [
+                "arithmetic",
+                "unsigned"
+            ],
+            "support": {
+                "chat": "https://gitter.im/arokettu/community",
+                "docs": "https://php-unsigned.readthedocs.io/",
+                "issues": "https://gitlab.com/sandfox/unsigned/-/issues",
+                "source": "https://gitlab.com/sandfox/unsigned"
+            },
+            "time": "2024-02-01T20:40:11+00:00"
+        },
         {
             "name": "bugsnag/bugsnag",
             "version": "v3.29.1",
@@ -1571,6 +1763,85 @@
             },
             "time": "2024-03-19T20:45:05+00:00"
         },
+        {
+            "name": "php-http/discovery",
+            "version": "1.19.4",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/php-http/discovery.git",
+                "reference": "0700efda8d7526335132360167315fdab3aeb599"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/php-http/discovery/zipball/0700efda8d7526335132360167315fdab3aeb599",
+                "reference": "0700efda8d7526335132360167315fdab3aeb599",
+                "shasum": ""
+            },
+            "require": {
+                "composer-plugin-api": "^1.0|^2.0",
+                "php": "^7.1 || ^8.0"
+            },
+            "conflict": {
+                "nyholm/psr7": "<1.0",
+                "zendframework/zend-diactoros": "*"
+            },
+            "provide": {
+                "php-http/async-client-implementation": "*",
+                "php-http/client-implementation": "*",
+                "psr/http-client-implementation": "*",
+                "psr/http-factory-implementation": "*",
+                "psr/http-message-implementation": "*"
+            },
+            "require-dev": {
+                "composer/composer": "^1.0.2|^2.0",
+                "graham-campbell/phpspec-skip-example-extension": "^5.0",
+                "php-http/httplug": "^1.0 || ^2.0",
+                "php-http/message-factory": "^1.0",
+                "phpspec/phpspec": "^5.1 || ^6.1 || ^7.3",
+                "sebastian/comparator": "^3.0.5 || ^4.0.8",
+                "symfony/phpunit-bridge": "^6.4.4 || ^7.0.1"
+            },
+            "type": "composer-plugin",
+            "extra": {
+                "class": "Http\\Discovery\\Composer\\Plugin",
+                "plugin-optional": true
+            },
+            "autoload": {
+                "psr-4": {
+                    "Http\\Discovery\\": "src/"
+                },
+                "exclude-from-classmap": [
+                    "src/Composer/Plugin.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Márk Sági-Kazár",
+                    "email": "mark.sagikazar@gmail.com"
+                }
+            ],
+            "description": "Finds and installs PSR-7, PSR-17, PSR-18 and HTTPlug implementations",
+            "homepage": "http://php-http.org",
+            "keywords": [
+                "adapter",
+                "client",
+                "discovery",
+                "factory",
+                "http",
+                "message",
+                "psr17",
+                "psr7"
+            ],
+            "support": {
+                "issues": "https://github.com/php-http/discovery/issues",
+                "source": "https://github.com/php-http/discovery/tree/1.19.4"
+            },
+            "time": "2024-03-29T13:00:05+00:00"
+        },
         {
             "name": "phpoption/phpoption",
             "version": "1.9.2",
@@ -3105,6 +3376,158 @@
             ],
             "time": "2024-05-31T15:07:36+00:00"
         },
+        {
+            "name": "symfony/polyfill-php81",
+            "version": "v1.30.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/polyfill-php81.git",
+                "reference": "3fb075789fb91f9ad9af537c4012d523085bd5af"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/polyfill-php81/zipball/3fb075789fb91f9ad9af537c4012d523085bd5af",
+                "reference": "3fb075789fb91f9ad9af537c4012d523085bd5af",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=7.1"
+            },
+            "type": "library",
+            "extra": {
+                "thanks": {
+                    "name": "symfony/polyfill",
+                    "url": "https://github.com/symfony/polyfill"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "bootstrap.php"
+                ],
+                "psr-4": {
+                    "Symfony\\Polyfill\\Php81\\": ""
+                },
+                "classmap": [
+                    "Resources/stubs"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Nicolas Grekas",
+                    "email": "p@tchwork.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony polyfill backporting some PHP 8.1+ features to lower PHP versions",
+            "homepage": "https://symfony.com",
+            "keywords": [
+                "compatibility",
+                "polyfill",
+                "portable",
+                "shim"
+            ],
+            "support": {
+                "source": "https://github.com/symfony/polyfill-php81/tree/v1.30.0"
+            },
+            "funding": [
+                {
+                    "url": "https://symfony.com/sponsor",
+                    "type": "custom"
+                },
+                {
+                    "url": "https://github.com/fabpot",
+                    "type": "github"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2024-06-19T12:30:46+00:00"
+        },
+        {
+            "name": "symfony/polyfill-php82",
+            "version": "v1.30.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/polyfill-php82.git",
+                "reference": "77ff49780f56906788a88974867ed68bc49fae5b"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/polyfill-php82/zipball/77ff49780f56906788a88974867ed68bc49fae5b",
+                "reference": "77ff49780f56906788a88974867ed68bc49fae5b",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=7.1"
+            },
+            "type": "library",
+            "extra": {
+                "thanks": {
+                    "name": "symfony/polyfill",
+                    "url": "https://github.com/symfony/polyfill"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "bootstrap.php"
+                ],
+                "psr-4": {
+                    "Symfony\\Polyfill\\Php82\\": ""
+                },
+                "classmap": [
+                    "Resources/stubs"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Nicolas Grekas",
+                    "email": "p@tchwork.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony polyfill backporting some PHP 8.2+ features to lower PHP versions",
+            "homepage": "https://symfony.com",
+            "keywords": [
+                "compatibility",
+                "polyfill",
+                "portable",
+                "shim"
+            ],
+            "support": {
+                "source": "https://github.com/symfony/polyfill-php82/tree/v1.30.0"
+            },
+            "funding": [
+                {
+                    "url": "https://symfony.com/sponsor",
+                    "type": "custom"
+                },
+                {
+                    "url": "https://github.com/fabpot",
+                    "type": "github"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2024-06-19T12:30:46+00:00"
+        },
         {
             "name": "symfony/service-contracts",
             "version": "v3.5.0",
diff --git a/library/includes/ucp/register.php b/library/includes/ucp/register.php
index fc5f422fe..d5b85a939 100644
--- a/library/includes/ucp/register.php
+++ b/library/includes/ucp/register.php
@@ -375,6 +375,27 @@ foreach ($profile_fields as $field => $can_edit) {
          */
         case 'avatar_ext_id':
             if ($submit && !bf($pr_data['user_opt'], 'user_opt', 'dis_avatar')) {
+                // Integration with MonsterID
+                if (!isset($_POST['delete_avatar']) && isset($_POST['use_monster_avatar'])) {
+                    $monsterAvatar = new Arokettu\MonsterID\Monster($pr_data['user_email'], $bb_cfg['avatars']['max_height']);
+                    $tempAvatar = tmpfile();
+                    $tempAvatarMeta = stream_get_meta_data($tempAvatar);
+                    $monsterAvatar->writeToStream($tempAvatar);
+
+                    // Manual filling $_FILES['avatar']
+                    $_FILES['avatar'] = array();
+                    if (!empty($tempAvatarMeta['uri']) && is_file($tempAvatarMeta['uri'])) {
+                        $_FILES['avatar'] = [
+                            'name' => 'MonsterID.png',
+                            'full_path' => 'MonsterID.png',
+                            'type' => 'image/png',
+                            'tmp_name' => $tempAvatarMeta['uri'],
+                            'error' => 0,
+                            'size' => filesize($tempAvatarMeta['uri'])
+                        ];
+                    }
+                }
+
                 if (isset($_POST['delete_avatar'])) {
                     delete_avatar($pr_data['user_id'], $pr_data['avatar_ext_id']);
                     $pr_data['avatar_ext_id'] = 0;
@@ -382,7 +403,7 @@ foreach ($profile_fields as $field => $can_edit) {
                 } elseif (!empty($_FILES['avatar']['name']) && $bb_cfg['avatars']['up_allowed']) {
                     $upload = new TorrentPier\Legacy\Common\Upload();
 
-                    if ($upload->init($bb_cfg['avatars'], $_FILES['avatar']) and $upload->store('avatar', $pr_data)) {
+                    if ($upload->init($bb_cfg['avatars'], $_FILES['avatar'], !isset($_POST['use_monster_avatar'])) and $upload->store('avatar', $pr_data)) {
                         $pr_data['avatar_ext_id'] = $upload->file_ext_id;
                         $db_data['avatar_ext_id'] = (int)$upload->file_ext_id;
                     } else {
diff --git a/library/language/source/main.php b/library/language/source/main.php
index ca3fa10d9..99f72c0ab 100644
--- a/library/language/source/main.php
+++ b/library/language/source/main.php
@@ -607,6 +607,7 @@ $lang['RETURN_PROFILE'] = 'Return to profile';
 $lang['SELECT_CATEGORY'] = 'Select category';
 
 $lang['DELETE_IMAGE'] = 'Delete image';
+$lang['SET_MONSTERID_AVATAR'] = 'Set avatar from MonsterID';
 $lang['CURRENT_IMAGE'] = 'Current image';
 
 $lang['NOTIFY_ON_PRIVMSG'] = 'Notify on new private message';
diff --git a/src/Legacy/Common/Upload.php b/src/Legacy/Common/Upload.php
index c6834fbae..7912a1292 100644
--- a/src/Legacy/Common/Upload.php
+++ b/src/Legacy/Common/Upload.php
@@ -36,6 +36,7 @@ class Upload
      */
     public array $file = [
         'name' => '',
+        'full_path' => '',
         'type' => '',
         'size' => 0,
         'tmp_name' => '',
diff --git a/styles/templates/default/usercp_register.tpl b/styles/templates/default/usercp_register.tpl
index 353bc53b3..aeddeb247 100644
--- a/styles/templates/default/usercp_register.tpl
+++ b/styles/templates/default/usercp_register.tpl
@@ -315,6 +315,7 @@
                         <td class="tCenter nowrap">
                             <p class="mrg_6">{AVATAR_IMG}</p>
                             <p><label><input type="checkbox" name="delete_avatar"/> {L_DELETE_IMAGE}</label></p>
+                            <p><label><input type="checkbox" name="use_monster_avatar"/> {L_SET_MONSTERID_AVATAR}</label></p>
                         </td>
                     </tr>
                 </table>