diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5df26b9fa43..144f6c06635 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -36,6 +36,7 @@ jobs:
         include:
           - {php-version: "8.2"} # Lint on lower PHP version to detected too early usage of new syntaxes
           - {php-version: "8.3"} # Lint on higher PHP version to detected deprecated elements usage
+          - {php-version: "8.4-rc"}
     env:
       COMPOSE_FILE: ".github/actions/docker-compose-app.yml"
       APPLICATION_ROOT: "${{ github.workspace }}"
@@ -73,9 +74,11 @@ jobs:
         run: |
           .github/actions/init_show-versions.sh
       - name: "Force used PHP version"
+        # Strip the stability suffix (e.g. "8.4-rc" -> "php:>=8.4")
         run: |
+          REQUIRED_PHP_VERSION="$(echo "${{ matrix.php-version }}" | cut -d '-' -f 1)"
           docker compose exec -T app composer config --unset platform.php
-          docker compose exec -T app composer require "php:>=${{ matrix.php-version }}" --ignore-platform-req=php+ --no-install --no-scripts
+          docker compose exec -T app composer require "php:>=$REQUIRED_PHP_VERSION" --ignore-platform-req=php+ --no-install --no-scripts
       - name: "Build dependencies / translations"
         run: |
           docker compose exec -T app .github/actions/init_build.sh
@@ -115,6 +118,7 @@ jobs:
             MATRIX='
               {
                 "include": [
+                  {"php-version": "8.4-rc", "db-image": "mariadb:11.4"},
                   {"php-version": "8.3", "db-image": "mariadb:11.4"},
                   {"php-version": "8.3", "db-image": "mysql:8.4"},
                   {"php-version": "8.2", "db-image": "mariadb:11.4"},
@@ -127,6 +131,7 @@ jobs:
             MATRIX='
               {
                 "include": [
+                  {"php-version": "8.4-rc", "db-image": "mariadb:11.4"},
                   {"php-version": "8.3", "db-image": "mariadb:11.4"},
                   {"php-version": "8.3", "db-image": "mysql:8.4"}
                 ]
diff --git a/composer.json b/composer.json
index d853eb43744..e93204d3d35 100644
--- a/composer.json
+++ b/composer.json
@@ -51,7 +51,7 @@
         "league/oauth2-server": "^9.0",
         "mexitek/phpcolors": "^1.0",
         "monolog/monolog": "^3.7",
-        "paragonie/sodium_compat": "^2.0",
+        "paragonie/sodium_compat": "^2.1",
         "phpdocumentor/reflection-docblock": "^5.4",
         "phpoffice/phpspreadsheet": "^2.2",
         "psr/cache": "^3.0",
@@ -99,8 +99,8 @@
     },
     "require-dev": {
         "ext-xml": "*",
-        "atoum/atoum": "^4.2",
-        "atoum/stubs": "^2.6",
+        "atoum/atoum": "dev-main#e43a6a84809635cf5dcdf80bf3c773e7cf1d5a04",
+        "atoum/stubs": "dev-master#fb8890f347a7ecf1e3cf2b5a139a8b038359a6ab",
         "friendsoftwig/twigcs": "^6.4",
         "glpi-project/tools": "^0.7",
         "mikey179/vfsstream": "^1.6",
@@ -182,19 +182,31 @@
         "post-install-cmd": [
             "@php -r \"file_put_contents('.composer.hash', sha1_file('composer.lock'));\"",
             "@php -f vendor/bin/build_hw_jsons",
-            "patch -f -p1 -d vendor/laminas/laminas-mail/ < tools/patches/laminas-mail-invalid-header-ignore.patch || true",
-            "patch -f -p1 -d vendor/laminas/laminas-mail/ < tools/patches/laminas-mail-address-no-length-check.patch || true",
-            "patch -f -p1 -d vendor/guzzlehttp/guzzle/ < tools/patches/guzzle-http-client-restrict-http-methods.patch || true"
+            "@patch"
         ],
         "post-update-cmd": [
             "@php -r \"file_put_contents('.composer.hash', sha1_file('composer.lock'));\"",
             "@php -f vendor/bin/build_hw_jsons",
-            "patch -f -p1 -d vendor/laminas/laminas-mail/ < tools/patches/laminas-mail-invalid-header-ignore.patch || true",
-            "patch -f -p1 -d vendor/laminas/laminas-mail/ < tools/patches/laminas-mail-address-no-length-check.patch || true",
-            "patch -f -p1 -d vendor/guzzlehttp/guzzle/ < tools/patches/guzzle-http-client-restrict-http-methods.patch || true"
+            "@patch"
         ],
         "build": [
             "bin/console dependencies install && bin/console locales:compile"
+        ],
+        "patch": [
+            "patch -f -p1 -d vendor/laminas/laminas-mail/ < tools/patches/laminas-mail-invalid-header-ignore.patch || true",
+            "patch -f -p1 -d vendor/laminas/laminas-mail/ < tools/patches/laminas-mail-address-no-length-check.patch || true",
+            "patch -f -p1 -d vendor/guzzlehttp/guzzle/ < tools/patches/guzzle-http-client-restrict-http-methods.patch || true",
+            "patch -f -p1 -d vendor/apereo/phpcas/ < tools/patches/apereo-phpcas-php84.patch || true",
+            "patch -f -p1 -d vendor/friendsoftwig/twigcs/ < tools/patches/friendsoftwig-twigcs-php84.patch || true",
+            "patch -f -p1 -d vendor/league/event/ < tools/patches/league-event-php84.patch || true",
+            "patch -f -p1 -d vendor/league/oauth2-client/ < tools/patches/league-oauth2-client-php84.patch || true",
+            "patch -f -p1 -d vendor/league/oauth2-server/ < tools/patches/league-oauth2-server-php84.patch || true",
+            "patch -f -p1 -d vendor/sabre/dav/ < tools/patches/sabre-dav-php84.patch || true",
+            "patch -f -p1 -d vendor/sabre/vobject/ < tools/patches/sabre-vobject-php84.patch || true",
+            "patch -f -p1 -d vendor/swaggest/json-diff/ < tools/patches/swaggest-json-diff-php84.patch || true",
+            "patch -f -p1 -d vendor/swaggest/json-schema/ < tools/patches/swaggest-json-schema-php84.patch || true",
+            "patch -f -p1 -d vendor/symfony/cache/ < tools/patches/symfony-cache-php84.patch || true",
+            "patch -f -p1 -d vendor/wapmorgan/unified-archive/ < tools/patches/wapmorgan-unified-archive-php84.patch || true"
         ]
     }
 }
diff --git a/composer.lock b/composer.lock
index b8dad9b3bd2..cd45a451a67 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": "2a1aacb3c8502970d63d335812826ee9",
+    "content-hash": "ba5fe16a1e13039f3bb864ab9390cf03",
     "packages": [
         {
             "name": "apereo/phpcas",
@@ -3403,16 +3403,16 @@
         },
         {
             "name": "paragonie/sodium_compat",
-            "version": "v2.0.1",
+            "version": "v2.1.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/paragonie/sodium_compat.git",
-                "reference": "f65c82939ab17aeff538f9bf6d582f65cc7f255e"
+                "reference": "a673d5f310477027cead2e2f2b6db5d8368157cb"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/paragonie/sodium_compat/zipball/f65c82939ab17aeff538f9bf6d582f65cc7f255e",
-                "reference": "f65c82939ab17aeff538f9bf6d582f65cc7f255e",
+                "url": "https://api.github.com/repos/paragonie/sodium_compat/zipball/a673d5f310477027cead2e2f2b6db5d8368157cb",
+                "reference": "a673d5f310477027cead2e2f2b6db5d8368157cb",
                 "shasum": ""
             },
             "require": {
@@ -3427,6 +3427,11 @@
                 "ext-sodium": "Better performance, password hashing (Argon2i), secure memory management (memzero), and better security."
             },
             "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "2.0.x-dev"
+                }
+            },
             "autoload": {
                 "files": [
                     "autoload.php"
@@ -3483,9 +3488,9 @@
             ],
             "support": {
                 "issues": "https://github.com/paragonie/sodium_compat/issues",
-                "source": "https://github.com/paragonie/sodium_compat/tree/v2.0.1"
+                "source": "https://github.com/paragonie/sodium_compat/tree/v2.1.0"
             },
-            "time": "2024-04-24T12:06:31+00:00"
+            "time": "2024-09-04T12:51:01+00:00"
         },
         {
             "name": "phpdocumentor/reflection-common",
@@ -4870,25 +4875,25 @@
         },
         {
             "name": "sabre/event",
-            "version": "5.1.4",
+            "version": "5.1.7",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sabre-io/event.git",
-                "reference": "d7da22897125d34d7eddf7977758191c06a74497"
+                "reference": "86d57e305c272898ba3c28e9bd3d65d5464587c2"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sabre-io/event/zipball/d7da22897125d34d7eddf7977758191c06a74497",
-                "reference": "d7da22897125d34d7eddf7977758191c06a74497",
+                "url": "https://api.github.com/repos/sabre-io/event/zipball/86d57e305c272898ba3c28e9bd3d65d5464587c2",
+                "reference": "86d57e305c272898ba3c28e9bd3d65d5464587c2",
                 "shasum": ""
             },
             "require": {
                 "php": "^7.1 || ^8.0"
             },
             "require-dev": {
-                "friendsofphp/php-cs-fixer": "~2.17.1",
+                "friendsofphp/php-cs-fixer": "~2.17.1||^3.63",
                 "phpstan/phpstan": "^0.12",
-                "phpunit/phpunit": "^7.5 || ^8.5 || ^9.0"
+                "phpunit/phpunit": "^7.5 || ^8.5 || ^9.6"
             },
             "type": "library",
             "autoload": {
@@ -4932,20 +4937,20 @@
                 "issues": "https://github.com/sabre-io/event/issues",
                 "source": "https://github.com/fruux/sabre-event"
             },
-            "time": "2021-11-04T06:51:17+00:00"
+            "time": "2024-08-27T11:23:05+00:00"
         },
         {
             "name": "sabre/http",
-            "version": "5.1.10",
+            "version": "5.1.12",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sabre-io/http.git",
-                "reference": "f9f3d1fba8916fa2f4ec25636c4fedc26cb94e02"
+                "reference": "dedff73f3995578bc942fa4c8484190cac14f139"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sabre-io/http/zipball/f9f3d1fba8916fa2f4ec25636c4fedc26cb94e02",
-                "reference": "f9f3d1fba8916fa2f4ec25636c4fedc26cb94e02",
+                "url": "https://api.github.com/repos/sabre-io/http/zipball/dedff73f3995578bc942fa4c8484190cac14f139",
+                "reference": "dedff73f3995578bc942fa4c8484190cac14f139",
                 "shasum": ""
             },
             "require": {
@@ -4957,9 +4962,9 @@
                 "sabre/uri": "^2.0"
             },
             "require-dev": {
-                "friendsofphp/php-cs-fixer": "~2.17.1",
+                "friendsofphp/php-cs-fixer": "~2.17.1||^3.63",
                 "phpstan/phpstan": "^0.12",
-                "phpunit/phpunit": "^7.5 || ^8.5 || ^9.0"
+                "phpunit/phpunit": "^7.5 || ^8.5 || ^9.6"
             },
             "suggest": {
                 "ext-curl": " to make http requests with the Client class"
@@ -4995,31 +5000,31 @@
                 "issues": "https://github.com/sabre-io/http/issues",
                 "source": "https://github.com/fruux/sabre-http"
             },
-            "time": "2023-08-18T01:55:28+00:00"
+            "time": "2024-08-27T16:07:41+00:00"
         },
         {
             "name": "sabre/uri",
-            "version": "2.3.3",
+            "version": "2.3.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sabre-io/uri.git",
-                "reference": "7e0e7dfd0b7e14346a27eabd66e843a6e7f1812b"
+                "reference": "b76524c22de90d80ca73143680a8e77b1266c291"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sabre-io/uri/zipball/7e0e7dfd0b7e14346a27eabd66e843a6e7f1812b",
-                "reference": "7e0e7dfd0b7e14346a27eabd66e843a6e7f1812b",
+                "url": "https://api.github.com/repos/sabre-io/uri/zipball/b76524c22de90d80ca73143680a8e77b1266c291",
+                "reference": "b76524c22de90d80ca73143680a8e77b1266c291",
                 "shasum": ""
             },
             "require": {
                 "php": "^7.4 || ^8.0"
             },
             "require-dev": {
-                "friendsofphp/php-cs-fixer": "^3.17",
-                "phpstan/extension-installer": "^1.3",
-                "phpstan/phpstan": "^1.10",
-                "phpstan/phpstan-phpunit": "^1.3",
-                "phpstan/phpstan-strict-rules": "^1.5",
+                "friendsofphp/php-cs-fixer": "^3.63",
+                "phpstan/extension-installer": "^1.4",
+                "phpstan/phpstan": "^1.12",
+                "phpstan/phpstan-phpunit": "^1.4",
+                "phpstan/phpstan-strict-rules": "^1.6",
                 "phpunit/phpunit": "^9.6"
             },
             "type": "library",
@@ -5055,7 +5060,7 @@
                 "issues": "https://github.com/sabre-io/uri/issues",
                 "source": "https://github.com/fruux/sabre-uri"
             },
-            "time": "2023-06-09T06:54:04+00:00"
+            "time": "2024-08-27T12:18:16+00:00"
         },
         {
             "name": "sabre/vobject",
@@ -5163,16 +5168,16 @@
         },
         {
             "name": "sabre/xml",
-            "version": "2.2.9",
+            "version": "2.2.10",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sabre-io/xml.git",
-                "reference": "88288712d45f694be3679a0db7dfb3770f08d4f0"
+                "reference": "0734b7af7f045d9ffb0018929750c492698a1536"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sabre-io/xml/zipball/88288712d45f694be3679a0db7dfb3770f08d4f0",
-                "reference": "88288712d45f694be3679a0db7dfb3770f08d4f0",
+                "url": "https://api.github.com/repos/sabre-io/xml/zipball/0734b7af7f045d9ffb0018929750c492698a1536",
+                "reference": "0734b7af7f045d9ffb0018929750c492698a1536",
                 "shasum": ""
             },
             "require": {
@@ -5184,7 +5189,7 @@
                 "sabre/uri": ">=1.0,<3.0.0"
             },
             "require-dev": {
-                "friendsofphp/php-cs-fixer": "~2.17.1",
+                "friendsofphp/php-cs-fixer": "~2.17.1||^3.63",
                 "phpstan/phpstan": "^0.12",
                 "phpunit/phpunit": "^7.5 || ^8.5 || ^9.6"
             },
@@ -5228,7 +5233,7 @@
                 "issues": "https://github.com/sabre-io/xml/issues",
                 "source": "https://github.com/fruux/sabre-xml"
             },
-            "time": "2024-07-26T12:32:40+00:00"
+            "time": "2024-08-27T15:55:05+00:00"
         },
         {
             "name": "scssphp/scssphp",
@@ -8899,16 +8904,16 @@
     "packages-dev": [
         {
             "name": "atoum/atoum",
-            "version": "4.2.0",
+            "version": "dev-main",
             "source": {
                 "type": "git",
                 "url": "https://github.com/atoum/atoum.git",
-                "reference": "fd9a339de252ea774ab755b3fd25dd19be2dbefb"
+                "reference": "e43a6a84809635cf5dcdf80bf3c773e7cf1d5a04"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/atoum/atoum/zipball/fd9a339de252ea774ab755b3fd25dd19be2dbefb",
-                "reference": "fd9a339de252ea774ab755b3fd25dd19be2dbefb",
+                "url": "https://api.github.com/repos/atoum/atoum/zipball/e43a6a84809635cf5dcdf80bf3c773e7cf1d5a04",
+                "reference": "e43a6a84809635cf5dcdf80bf3c773e7cf1d5a04",
                 "shasum": ""
             },
             "require": {
@@ -8929,6 +8934,7 @@
                 "ext-mbstring": "Provides support for UTF-8 strings",
                 "ext-xdebug": "Provides code coverage report (>= 2.3)"
             },
+            "default-branch": true,
             "bin": [
                 "bin/atoum"
             ],
@@ -8980,27 +8986,28 @@
             ],
             "support": {
                 "issues": "https://github.com/atoum/atoum/issues",
-                "source": "https://github.com/atoum/atoum/tree/4.2.0"
+                "source": "https://github.com/atoum/atoum/tree/main"
             },
-            "time": "2023-07-30T12:52:23+00:00"
+            "time": "2024-07-31T12:02:10+00:00"
         },
         {
             "name": "atoum/stubs",
-            "version": "2.6.0",
+            "version": "dev-master",
             "source": {
                 "type": "git",
                 "url": "https://github.com/atoum/stubs.git",
-                "reference": "df8b73b0358de7283ecba91d8f4a9683f583993d"
+                "reference": "fb8890f347a7ecf1e3cf2b5a139a8b038359a6ab"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/atoum/stubs/zipball/df8b73b0358de7283ecba91d8f4a9683f583993d",
-                "reference": "df8b73b0358de7283ecba91d8f4a9683f583993d",
+                "url": "https://api.github.com/repos/atoum/stubs/zipball/fb8890f347a7ecf1e3cf2b5a139a8b038359a6ab",
+                "reference": "fb8890f347a7ecf1e3cf2b5a139a8b038359a6ab",
                 "shasum": ""
             },
             "suggest": {
                 "atoum/atoum": "Include atoum in your projet dependencies"
             },
+            "default-branch": true,
             "type": "library",
             "extra": {
                 "branch-alias": {
@@ -9033,7 +9040,7 @@
                 "issues": "https://github.com/atoum/stubs/issues",
                 "source": "https://github.com/atoum/stubs/tree/master"
             },
-            "time": "2018-01-29T22:41:37+00:00"
+            "time": "2024-07-30T18:02:37+00:00"
         },
         {
             "name": "friendsoftwig/twigcs",
@@ -9650,32 +9657,32 @@
         },
         {
             "name": "phpunit/php-code-coverage",
-            "version": "11.0.5",
+            "version": "11.0.6",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/php-code-coverage.git",
-                "reference": "19b6365ab8b59a64438c0c3f4241feeb480c9861"
+                "reference": "ebdffc9e09585dafa71b9bffcdb0a229d4704c45"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/php-code-coverage/zipball/19b6365ab8b59a64438c0c3f4241feeb480c9861",
-                "reference": "19b6365ab8b59a64438c0c3f4241feeb480c9861",
+                "url": "https://api.github.com/repos/sebastianbergmann/php-code-coverage/zipball/ebdffc9e09585dafa71b9bffcdb0a229d4704c45",
+                "reference": "ebdffc9e09585dafa71b9bffcdb0a229d4704c45",
                 "shasum": ""
             },
             "require": {
                 "ext-dom": "*",
                 "ext-libxml": "*",
                 "ext-xmlwriter": "*",
-                "nikic/php-parser": "^5.0",
+                "nikic/php-parser": "^5.1.0",
                 "php": ">=8.2",
-                "phpunit/php-file-iterator": "^5.0",
-                "phpunit/php-text-template": "^4.0",
-                "sebastian/code-unit-reverse-lookup": "^4.0",
-                "sebastian/complexity": "^4.0",
-                "sebastian/environment": "^7.0",
-                "sebastian/lines-of-code": "^3.0",
-                "sebastian/version": "^5.0",
-                "theseer/tokenizer": "^1.2.0"
+                "phpunit/php-file-iterator": "^5.0.1",
+                "phpunit/php-text-template": "^4.0.1",
+                "sebastian/code-unit-reverse-lookup": "^4.0.1",
+                "sebastian/complexity": "^4.0.1",
+                "sebastian/environment": "^7.2.0",
+                "sebastian/lines-of-code": "^3.0.1",
+                "sebastian/version": "^5.0.1",
+                "theseer/tokenizer": "^1.2.3"
             },
             "require-dev": {
                 "phpunit/phpunit": "^11.0"
@@ -9687,7 +9694,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-main": "11.0-dev"
+                    "dev-main": "11.0.x-dev"
                 }
             },
             "autoload": {
@@ -9716,7 +9723,7 @@
             "support": {
                 "issues": "https://github.com/sebastianbergmann/php-code-coverage/issues",
                 "security": "https://github.com/sebastianbergmann/php-code-coverage/security/policy",
-                "source": "https://github.com/sebastianbergmann/php-code-coverage/tree/11.0.5"
+                "source": "https://github.com/sebastianbergmann/php-code-coverage/tree/11.0.6"
             },
             "funding": [
                 {
@@ -9724,20 +9731,20 @@
                     "type": "github"
                 }
             ],
-            "time": "2024-07-03T05:05:37+00:00"
+            "time": "2024-08-22T04:37:56+00:00"
         },
         {
             "name": "phpunit/php-file-iterator",
-            "version": "5.0.1",
+            "version": "5.1.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/php-file-iterator.git",
-                "reference": "6ed896bf50bbbfe4d504a33ed5886278c78e4a26"
+                "reference": "118cfaaa8bc5aef3287bf315b6060b1174754af6"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/php-file-iterator/zipball/6ed896bf50bbbfe4d504a33ed5886278c78e4a26",
-                "reference": "6ed896bf50bbbfe4d504a33ed5886278c78e4a26",
+                "url": "https://api.github.com/repos/sebastianbergmann/php-file-iterator/zipball/118cfaaa8bc5aef3287bf315b6060b1174754af6",
+                "reference": "118cfaaa8bc5aef3287bf315b6060b1174754af6",
                 "shasum": ""
             },
             "require": {
@@ -9777,7 +9784,7 @@
             "support": {
                 "issues": "https://github.com/sebastianbergmann/php-file-iterator/issues",
                 "security": "https://github.com/sebastianbergmann/php-file-iterator/security/policy",
-                "source": "https://github.com/sebastianbergmann/php-file-iterator/tree/5.0.1"
+                "source": "https://github.com/sebastianbergmann/php-file-iterator/tree/5.1.0"
             },
             "funding": [
                 {
@@ -9785,7 +9792,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2024-07-03T05:06:37+00:00"
+            "time": "2024-08-27T05:02:59+00:00"
         },
         {
             "name": "phpunit/php-invoker",
@@ -9973,16 +9980,16 @@
         },
         {
             "name": "phpunit/phpunit",
-            "version": "11.2.6",
+            "version": "11.3.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "1dc0fedac703199e8704de085e47dd46bac0dde4"
+                "reference": "8a4de85cc4a78c59dd31cc4ef454b0029f8440dc"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/1dc0fedac703199e8704de085e47dd46bac0dde4",
-                "reference": "1dc0fedac703199e8704de085e47dd46bac0dde4",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/8a4de85cc4a78c59dd31cc4ef454b0029f8440dc",
+                "reference": "8a4de85cc4a78c59dd31cc4ef454b0029f8440dc",
                 "shasum": ""
             },
             "require": {
@@ -9992,25 +9999,25 @@
                 "ext-mbstring": "*",
                 "ext-xml": "*",
                 "ext-xmlwriter": "*",
-                "myclabs/deep-copy": "^1.10.1",
-                "phar-io/manifest": "^2.0.3",
-                "phar-io/version": "^3.0.2",
+                "myclabs/deep-copy": "^1.12.0",
+                "phar-io/manifest": "^2.0.4",
+                "phar-io/version": "^3.2.1",
                 "php": ">=8.2",
-                "phpunit/php-code-coverage": "^11.0",
-                "phpunit/php-file-iterator": "^5.0",
-                "phpunit/php-invoker": "^5.0",
-                "phpunit/php-text-template": "^4.0",
-                "phpunit/php-timer": "^7.0",
-                "sebastian/cli-parser": "^3.0",
-                "sebastian/code-unit": "^3.0",
-                "sebastian/comparator": "^6.0",
-                "sebastian/diff": "^6.0",
-                "sebastian/environment": "^7.0",
-                "sebastian/exporter": "^6.1.2",
-                "sebastian/global-state": "^7.0",
-                "sebastian/object-enumerator": "^6.0",
-                "sebastian/type": "^5.0",
-                "sebastian/version": "^5.0"
+                "phpunit/php-code-coverage": "^11.0.6",
+                "phpunit/php-file-iterator": "^5.1.0",
+                "phpunit/php-invoker": "^5.0.1",
+                "phpunit/php-text-template": "^4.0.1",
+                "phpunit/php-timer": "^7.0.1",
+                "sebastian/cli-parser": "^3.0.2",
+                "sebastian/code-unit": "^3.0.1",
+                "sebastian/comparator": "^6.0.2",
+                "sebastian/diff": "^6.0.2",
+                "sebastian/environment": "^7.2.0",
+                "sebastian/exporter": "^6.1.3",
+                "sebastian/global-state": "^7.0.2",
+                "sebastian/object-enumerator": "^6.0.1",
+                "sebastian/type": "^5.0.1",
+                "sebastian/version": "^5.0.1"
             },
             "suggest": {
                 "ext-soap": "To be able to generate mocks based on WSDL files"
@@ -10021,7 +10028,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-main": "11.2-dev"
+                    "dev-main": "11.3-dev"
                 }
             },
             "autoload": {
@@ -10053,7 +10060,7 @@
             "support": {
                 "issues": "https://github.com/sebastianbergmann/phpunit/issues",
                 "security": "https://github.com/sebastianbergmann/phpunit/security/policy",
-                "source": "https://github.com/sebastianbergmann/phpunit/tree/11.2.6"
+                "source": "https://github.com/sebastianbergmann/phpunit/tree/11.3.2"
             },
             "funding": [
                 {
@@ -10069,7 +10076,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2024-07-03T05:51:49+00:00"
+            "time": "2024-09-03T12:00:26+00:00"
         },
         {
             "name": "sebastian/cli-parser",
@@ -10243,16 +10250,16 @@
         },
         {
             "name": "sebastian/comparator",
-            "version": "6.0.1",
+            "version": "6.0.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/comparator.git",
-                "reference": "131942b86d3587291067a94f295498ab6ac79c20"
+                "reference": "450d8f237bd611c45b5acf0733ce43e6bb280f81"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/comparator/zipball/131942b86d3587291067a94f295498ab6ac79c20",
-                "reference": "131942b86d3587291067a94f295498ab6ac79c20",
+                "url": "https://api.github.com/repos/sebastianbergmann/comparator/zipball/450d8f237bd611c45b5acf0733ce43e6bb280f81",
+                "reference": "450d8f237bd611c45b5acf0733ce43e6bb280f81",
                 "shasum": ""
             },
             "require": {
@@ -10308,7 +10315,7 @@
             "support": {
                 "issues": "https://github.com/sebastianbergmann/comparator/issues",
                 "security": "https://github.com/sebastianbergmann/comparator/security/policy",
-                "source": "https://github.com/sebastianbergmann/comparator/tree/6.0.1"
+                "source": "https://github.com/sebastianbergmann/comparator/tree/6.0.2"
             },
             "funding": [
                 {
@@ -10316,7 +10323,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2024-07-03T04:48:07+00:00"
+            "time": "2024-08-12T06:07:25+00:00"
         },
         {
             "name": "sebastian/complexity",
@@ -11636,7 +11643,10 @@
     ],
     "aliases": [],
     "minimum-stability": "stable",
-    "stability-flags": [],
+    "stability-flags": {
+        "atoum/atoum": 20,
+        "atoum/stubs": 20
+    },
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
diff --git a/public/index.php b/public/index.php
index caa63615fa3..0571432a332 100755
--- a/public/index.php
+++ b/public/index.php
@@ -37,8 +37,8 @@
 
 // Check PHP version not to have trouble
 // Need to be the very fist step before any include
-if (version_compare(PHP_VERSION, '8.2.0', '<') || version_compare(PHP_VERSION, '8.3.999', '>')) {
-    exit('PHP version must be between 8.2 and 8.3.');
+if (version_compare(PHP_VERSION, '8.2.0', '<') || version_compare(PHP_VERSION, '8.4.999', '>')) {
+    exit('PHP version must be between 8.2 and 8.4.');
 }
 
 // Check the resources state before trying to instanciate the Kernel.
diff --git a/src/Consumable.php b/src/Consumable.php
index b86a14325ac..092a1ae1e83 100644
--- a/src/Consumable.php
+++ b/src/Consumable.php
@@ -197,7 +197,7 @@ public static function getMassiveActionsForItemtype(
         array &$actions,
         $itemtype,
         $is_deleted = 0,
-        CommonDBTM $checkitem = null
+        ?CommonDBTM $checkitem = null
     ) {
         // Special actions only for self
         if ($itemtype !== static::class) {
diff --git a/src/DBmysql.php b/src/DBmysql.php
index 97149ab51fe..244880fc98a 100644
--- a/src/DBmysql.php
+++ b/src/DBmysql.php
@@ -365,7 +365,7 @@ public function escape($string)
      */
     public function query($query)
     {
-        trigger_error('Executing direct queries is not allowed!', E_USER_ERROR);
+        throw new \Exception('Executing direct queries is not allowed!');
     }
 
     /**
@@ -465,7 +465,7 @@ static function ($warning) {
      */
     public function queryOrDie($query, $message = '')
     {
-        trigger_error('Executing direct queries is not allowed!', E_USER_ERROR);
+        throw new \Exception('Executing direct queries is not allowed!');
     }
 
     /**
diff --git a/src/Glpi/Asset/Asset_PeripheralAsset.php b/src/Glpi/Asset/Asset_PeripheralAsset.php
index a9ba93ecb1e..3df0f0cb398 100644
--- a/src/Glpi/Asset/Asset_PeripheralAsset.php
+++ b/src/Glpi/Asset/Asset_PeripheralAsset.php
@@ -257,7 +257,7 @@ public static function getMassiveActionsForItemtype(
         array &$actions,
         $itemtype,
         $is_deleted = false,
-        CommonDBTM $checkitem = null
+        ?CommonDBTM $checkitem = null
     ) {
         $action_prefix = __CLASS__ . MassiveAction::CLASS_ACTION_SEPARATOR;
         $specificities = self::getRelationMassiveActionsSpecificities();
diff --git a/src/Glpi/DBAL/QueryFunction.php b/src/Glpi/DBAL/QueryFunction.php
index 62957206db5..d0674371e74 100644
--- a/src/Glpi/DBAL/QueryFunction.php
+++ b/src/Glpi/DBAL/QueryFunction.php
@@ -171,7 +171,7 @@ public static function ifnull(string|QueryExpression $expression, string|QueryEx
      * @param string|null $alias Function result alias (will be automatically quoted)
      * @return QueryExpression
      */
-    public static function groupConcat(string|QueryExpression $expression, ?string $separator = null, bool $distinct = false, array|string $order_by = null, ?string $alias = null): QueryExpression
+    public static function groupConcat(string|QueryExpression $expression, ?string $separator = null, bool $distinct = false, array|string|null $order_by = null, ?string $alias = null): QueryExpression
     {
         /** @var \DBmysql $DB */
         global $DB;
@@ -305,7 +305,7 @@ public static function replace(string|QueryExpression $expression, string|QueryE
      * @param string|null $alias Function result alias (will be automatically quoted)
      * @return QueryExpression
      */
-    public static function fromUnixtime(string|QueryExpression $expression, string|QueryExpression $format = null, ?string $alias = null): QueryExpression
+    public static function fromUnixtime(string|QueryExpression $expression, string|QueryExpression|null $format = null, ?string $alias = null): QueryExpression
     {
         $params = [$expression];
         if ($format !== null) {
@@ -429,7 +429,7 @@ public static function timediff(string|QueryExpression $expression1, string|Quer
      * @param string|null $alias Function result alias (will be automatically quoted)
      * @return QueryExpression
      */
-    public static function unixTimestamp(string|QueryExpression $expression = null, ?string $alias = null): QueryExpression
+    public static function unixTimestamp(string|QueryExpression|null $expression = null, ?string $alias = null): QueryExpression
     {
         $params = [];
         if ($expression !== null) {
diff --git a/src/Glpi/Dashboard/FakeProvider.php b/src/Glpi/Dashboard/FakeProvider.php
index b651aca0aea..be12a88f15a 100644
--- a/src/Glpi/Dashboard/FakeProvider.php
+++ b/src/Glpi/Dashboard/FakeProvider.php
@@ -124,7 +124,7 @@ private static function getItemCount(?string $itemtype = null)
         return $values[$itemtype] ?? null;
     }
 
-    public static function bigNumberItem(CommonDBTM $item = null, array $params = []): array
+    public static function bigNumberItem(?CommonDBTM $item = null, array $params = []): array
     {
         return [
             'number' => self::getItemCount($item::class) ?? 1500,
@@ -277,7 +277,7 @@ public static function nbTicketsByAgreementStatusAndTechnicianGroup(array $param
         ];
     }
 
-    public static function nbItemByFk(CommonDBTM $item = null, CommonDBTM $fk_item = null, array $params = []): array
+    public static function nbItemByFk(?CommonDBTM $item = null, ?CommonDBTM $fk_item = null, array $params = []): array
     {
         $item_counts = self::getItemCount();
         $number_fk = $item_counts[$fk_item::class] ?? 20;
@@ -305,7 +305,7 @@ public static function nbItemByFk(CommonDBTM $item = null, CommonDBTM $fk_item =
         ];
     }
 
-    public static function articleListItem(CommonDBTM $item = null, array $params = []): array
+    public static function articleListItem(?CommonDBTM $item = null, array $params = []): array
     {
         $data = [];
         for ($i = 0; $i < 5; $i++) {
diff --git a/src/Glpi/Features/State.php b/src/Glpi/Features/State.php
index ede86e18a26..88776e4fb09 100644
--- a/src/Glpi/Features/State.php
+++ b/src/Glpi/Features/State.php
@@ -50,12 +50,11 @@ private function checkSetup(): void
         global $CFG_GLPI;
 
         if (!in_array(static::class, $CFG_GLPI['state_types'])) {
-            trigger_error(
+            throw new \LogicException(
                 sprintf(
                     'Class %s must be present in $CFG_GLPI[\'state_types\']',
                     static::class
-                ),
-                E_USER_ERROR
+                )
             );
         }
     }
diff --git a/src/Glpi/Marketplace/Controller.php b/src/Glpi/Marketplace/Controller.php
index c982a537034..8253810146d 100644
--- a/src/Glpi/Marketplace/Controller.php
+++ b/src/Glpi/Marketplace/Controller.php
@@ -158,7 +158,7 @@ private static function getPluginVersionInfo(array $plugin, string $version): ?a
      * @param ?string $version Download a specific version of the plugin
      * @return bool
      */
-    public function downloadPlugin($auto_install = true, string $version = null): bool
+    public function downloadPlugin($auto_install = true, ?string $version = null): bool
     {
         if (!self::hasWriteAccess()) {
             return false;
@@ -463,7 +463,7 @@ public function getRequiredOffers(): array
      *
      * @return bool
      */
-    public function canBeDownloaded(string $version = null)
+    public function canBeDownloaded(?string $version = null)
     {
         $api        = self::getAPI();
         $api_plugin = $api->getPlugin($this->plugin_key);
diff --git a/src/Glpi/System/Log/LogParser.php b/src/Glpi/System/Log/LogParser.php
index afb3fc4af5b..fff81594eb9 100644
--- a/src/Glpi/System/Log/LogParser.php
+++ b/src/Glpi/System/Log/LogParser.php
@@ -124,7 +124,7 @@ public function getLogFileInfo(string $filepath): ?array
      *
      * @return array|null
      */
-    public function parseLogFile(string $filepath, int $max_nb_lines = null): ?array
+    public function parseLogFile(string $filepath, ?int $max_nb_lines = null): ?array
     {
         /** @var array $CFG_GLPI */
         global $CFG_GLPI;
diff --git a/src/IPAddress.php b/src/IPAddress.php
index 2c90baccff2..c3597a30a53 100644
--- a/src/IPAddress.php
+++ b/src/IPAddress.php
@@ -1276,9 +1276,9 @@ private static function getCriteriaLinkedToNetwork(IPNetwork $network): array
      * @param array $options
      **/
     public static function getHTMLTableCellsForItem(
-        HTMLTableRow $row = null,
-        CommonDBTM $item = null,
-        HTMLTableCell $father = null,
+        ?HTMLTableRow $row = null,
+        ?CommonDBTM $item = null,
+        ?HTMLTableCell $father = null,
         array $options = []
     ) {
         /** @var \DBmysql $DB */
diff --git a/src/Line.php b/src/Line.php
index fcfa057c5de..70ce1a5d453 100644
--- a/src/Line.php
+++ b/src/Line.php
@@ -237,7 +237,7 @@ public static function getIcon()
         return "ti ti-phone-calling";
     }
 
-    public static function getMassiveActionsForItemtype(array &$actions, $itemtype, $is_deleted = 0, CommonDBTM $checkitem = null)
+    public static function getMassiveActionsForItemtype(array &$actions, $itemtype, $is_deleted = 0, ?CommonDBTM $checkitem = null)
     {
         /** @var array $CFG_GLPI */
         global $CFG_GLPI;
diff --git a/src/QueuedWebhook.php b/src/QueuedWebhook.php
index 58842e07c99..cc1b2621dee 100644
--- a/src/QueuedWebhook.php
+++ b/src/QueuedWebhook.php
@@ -559,7 +559,7 @@ public static function getPendings($send_time = null, $limit = 20, $extra_where
      *
      * @return integer either 0 or 1
      **/
-    public static function cronQueuedWebhook(CronTask $task = null)
+    public static function cronQueuedWebhook(?CronTask $task = null)
     {
         $cron_status = 0;
 
@@ -585,7 +585,7 @@ public static function cronQueuedWebhook(CronTask $task = null)
      *
      * @return integer either 0 or 1
      **/
-    public static function cronQueuedWebhookClean(CronTask $task = null)
+    public static function cronQueuedWebhookClean(?CronTask $task = null)
     {
         /** @var \DBmysql $DB */
         global $DB;
diff --git a/src/Reservation.php b/src/Reservation.php
index e317a17d8d7..12cc97f87ff 100644
--- a/src/Reservation.php
+++ b/src/Reservation.php
@@ -1153,7 +1153,7 @@ public static function getIcon()
         return "ti ti-calendar-event";
     }
 
-    public static function getMassiveActionsForItemtype(array &$actions, $itemtype, $is_deleted = 0, CommonDBTM $checkitem = null)
+    public static function getMassiveActionsForItemtype(array &$actions, $itemtype, $is_deleted = 0, ?CommonDBTM $checkitem = null)
     {
         /** @var array $CFG_GLPI */
         global $CFG_GLPI;
diff --git a/src/Toolbox.php b/src/Toolbox.php
index ccfd484270d..53ba08bf6bb 100644
--- a/src/Toolbox.php
+++ b/src/Toolbox.php
@@ -261,7 +261,7 @@ public static function decodeFromUtf8($string, $to_charset = "ISO-8859-1")
      *
      * @return void
      **/
-    private static function log(LoggerInterface $logger = null, $level = LogLevel::WARNING, $args = null)
+    private static function log(?LoggerInterface $logger = null, $level = LogLevel::WARNING, $args = null)
     {
         static $tps = 0;
 
diff --git a/src/autoload/constants.php b/src/autoload/constants.php
index e8ec0791909..d737740f34e 100644
--- a/src/autoload/constants.php
+++ b/src/autoload/constants.php
@@ -45,7 +45,7 @@
 );
 
 define('GLPI_MIN_PHP', '8.2'); // Must also be changed in top of public/index.php
-define('GLPI_MAX_PHP', '8.3'); // Must also be changed in top of public/index.php
+define('GLPI_MAX_PHP', '8.4'); // Must also be changed in top of public/index.php
 define('GLPI_YEAR', '2024');
 
 //Define a global recipient address for email notifications
diff --git a/tests/functional/State.php b/tests/functional/State.php
index 9b55c1927ab..94d841897e3 100644
--- a/tests/functional/State.php
+++ b/tests/functional/State.php
@@ -208,15 +208,12 @@ public function testIsStateVisible(): void
         unset($CFG_GLPI['state_types'][0]);
         $this->boolean(method_exists($itemtype, 'isStateVisible'))->isTrue($itemtype . ' misses isStateVisible() method!');
 
-        $this->when(
+        $this->exception(
             function () use ($item, $states_id) {
                 $this->boolean($item->isStateVisible($states_id))->isTrue();
             }
-        )
-            ->error()
-            ->withType(E_USER_ERROR)
-            ->withMessage(sprintf('Class %s must be present in $CFG_GLPI[\'state_types\']', $itemtype))
-            ->exists();
+        )->isInstanceOf(\LogicException::class)
+         ->hasMessage(sprintf('Class %s must be present in $CFG_GLPI[\'state_types\']', $itemtype));
     }
 
     public function testGetStateVisibilityCriteria(): void
diff --git a/tests/src/FormTesterTrait.php b/tests/src/FormTesterTrait.php
index bf459dddc7c..83cf4a9c6ce 100644
--- a/tests/src/FormTesterTrait.php
+++ b/tests/src/FormTesterTrait.php
@@ -149,7 +149,7 @@ protected function createForm(FormBuilder $builder): Form
     protected function getQuestionId(
         Form $form,
         string $question_name,
-        string $section_name = null,
+        ?string $section_name = null,
     ): int {
         // Make sure form is up to date
         $form->getFromDB($form->getID());
@@ -227,7 +227,7 @@ protected function getSectionId(
     protected function getCommentId(
         Form $form,
         string $comment_name,
-        string $section_name = null,
+        ?string $section_name = null,
     ): int {
         // Make sure form is up to date
         $form->getFromDB($form->getID());
diff --git a/tools/patches/apereo-phpcas-php84.patch b/tools/patches/apereo-phpcas-php84.patch
new file mode 100644
index 00000000000..6df6e7d594c
--- /dev/null
+++ b/tools/patches/apereo-phpcas-php84.patch
@@ -0,0 +1,35 @@
+diff --git a/source/CAS.php b/source/CAS.php
+index df6bc82..da145bc 100644
+--- a/source/CAS.php
++++ b/source/CAS.php
+@@ -347,7 +347,7 @@ class phpCAS
+      */
+     public static function client($server_version, $server_hostname,
+         $server_port, $server_uri, $service_base_url,
+-        $changeSessionID = true, \SessionHandlerInterface $sessionHandler = null
++        $changeSessionID = true, ?\SessionHandlerInterface $sessionHandler = null
+     ) {
+         phpCAS :: traceBegin();
+         if (is_object(self::$_PHPCAS_CLIENT)) {
+@@ -402,7 +402,7 @@ class phpCAS
+      */
+     public static function proxy($server_version, $server_hostname,
+         $server_port, $server_uri, $service_base_url,
+-        $changeSessionID = true, \SessionHandlerInterface $sessionHandler = null
++        $changeSessionID = true, ?\SessionHandlerInterface $sessionHandler = null
+     ) {
+         phpCAS :: traceBegin();
+         if (is_object(self::$_PHPCAS_CLIENT)) {
+diff --git a/source/CAS/Client.php b/source/CAS/Client.php
+index 8ca9711..42709e9 100644
+--- a/source/CAS/Client.php
++++ b/source/CAS/Client.php
+@@ -938,7 +938,7 @@ class CAS_Client
+         $server_uri,
+         $service_base_url,
+         $changeSessionID = true,
+-        \SessionHandlerInterface $sessionHandler = null
++        ?\SessionHandlerInterface $sessionHandler = null
+     ) {
+         // Argument validation
+         if (gettype($server_version) != 'string')
diff --git a/tools/patches/friendsoftwig-twigcs-php84.patch b/tools/patches/friendsoftwig-twigcs-php84.patch
new file mode 100644
index 00000000000..2132dad7200
--- /dev/null
+++ b/tools/patches/friendsoftwig-twigcs-php84.patch
@@ -0,0 +1,100 @@
+diff --git a/src/RegEngine/Checker/Handler.php b/src/RegEngine/Checker/Handler.php
+index e29974a..91253be 100644
+--- a/src/RegEngine/Checker/Handler.php
++++ b/src/RegEngine/Checker/Handler.php
+@@ -11,7 +11,7 @@ class Handler
+ 
+     private ?Handler $parent;
+ 
+-    public function __construct(self $parent = null)
++    public function __construct(?self $parent = null)
+     {
+         $this->parent = $parent;
+     }
+diff --git a/src/Rule/AbstractRule.php b/src/Rule/AbstractRule.php
+index 1246f6c..443f539 100644
+--- a/src/Rule/AbstractRule.php
++++ b/src/Rule/AbstractRule.php
+@@ -45,7 +45,7 @@ protected function getNextSignificantToken(TokenStream $tokens, int $skip = 0):
+         return StreamNavigator::getNextSignificantToken($tokens, $skip);
+     }
+ 
+-    protected function skipTo(TokenStream $tokens, int $tokenType, string $tokenValue = null)
++    protected function skipTo(TokenStream $tokens, int $tokenType, ?string $tokenValue = null)
+     {
+         return StreamNavigator::skipTo($tokens, $tokenType, $tokenValue);
+     }
+diff --git a/src/Rule/UnusedMacro.php b/src/Rule/UnusedMacro.php
+index ad2faa2..57b6ac3 100644
+--- a/src/Rule/UnusedMacro.php
++++ b/src/Rule/UnusedMacro.php
+@@ -11,7 +11,7 @@ class UnusedMacro extends AbstractRule implements RuleInterface
+ {
+     public TemplateResolverInterface $loader;
+ 
+-    public function __construct(int $severity, TemplateResolverInterface $loader = null)
++    public function __construct(int $severity, ?TemplateResolverInterface $loader = null)
+     {
+         $this->loader = $loader ?: new NullResolver();
+ 
+diff --git a/src/Rule/UnusedVariable.php b/src/Rule/UnusedVariable.php
+index f22140b..abecf66 100644
+--- a/src/Rule/UnusedVariable.php
++++ b/src/Rule/UnusedVariable.php
+@@ -11,7 +11,7 @@ class UnusedVariable extends AbstractRule implements RuleInterface
+ {
+     public TemplateResolverInterface $loader;
+ 
+-    public function __construct(int $severity, TemplateResolverInterface $loader = null)
++    public function __construct(int $severity, ?TemplateResolverInterface $loader = null)
+     {
+         $this->loader = $loader ?: new NullResolver();
+ 
+diff --git a/src/TwigPort/SyntaxError.php b/src/TwigPort/SyntaxError.php
+index 8a26eba..3d08171 100644
+--- a/src/TwigPort/SyntaxError.php
++++ b/src/TwigPort/SyntaxError.php
+@@ -20,7 +20,7 @@ class SyntaxError extends \Exception
+      * @param int         $lineno  The template line where the error occurred
+      * @param Source|null $source  The source context where the error occurred
+      */
+-    public function __construct(string $message, int $lineno = -1, int $columnno = -1, Source $source = null)
++    public function __construct(string $message, int $lineno = -1, int $columnno = -1, ?Source $source = null)
+     {
+         parent::__construct($message);
+ 
+diff --git a/src/TwigPort/TokenStream.php b/src/TwigPort/TokenStream.php
+index d2b3a90..82f4f46 100644
+--- a/src/TwigPort/TokenStream.php
++++ b/src/TwigPort/TokenStream.php
+@@ -15,7 +15,7 @@ final class TokenStream
+     private int $current = 0;
+     private Source $source;
+ 
+-    public function __construct(array $tokens, Source $source = null)
++    public function __construct(array $tokens, ?Source $source = null)
+     {
+         $this->tokens = $tokens;
+         $this->source = $source ?: new Source('', '');
+@@ -51,7 +51,7 @@ public function nextIf($primary, $secondary = null)
+         }
+     }
+ 
+-    public function expect($type, $value = null, string $message = null): Token
++    public function expect($type, $value = null, ?string $message = null): Token
+     {
+         $token = $this->tokens[$this->current];
+ 
+diff --git a/src/Util/StreamNavigator.php b/src/Util/StreamNavigator.php
+index 573d577..cf58dd4 100644
+--- a/src/Util/StreamNavigator.php
++++ b/src/Util/StreamNavigator.php
+@@ -47,7 +47,7 @@ public static function getNextSignificantToken(TokenStream $tokens, int $skip =
+         return null;
+     }
+ 
+-    public static function skipTo(TokenStream $tokens, int $tokenType, string $tokenValue = null)
++    public static function skipTo(TokenStream $tokens, int $tokenType, ?string $tokenValue = null)
+     {
+         while (!$tokens->isEOF()) {
+             $continue = $tokens->getCurrent()->getType() !== $tokenType;
diff --git a/tools/patches/league-event-php84.patch b/tools/patches/league-event-php84.patch
new file mode 100644
index 00000000000..d728114427f
--- /dev/null
+++ b/tools/patches/league-event-php84.patch
@@ -0,0 +1,13 @@
+diff --git a/src/EventDispatcher.php b/src/EventDispatcher.php
+index 6c5128f..35fdaea 100644
+--- a/src/EventDispatcher.php
++++ b/src/EventDispatcher.php
+@@ -14,7 +14,7 @@ class EventDispatcher implements EventDispatchingListenerRegistry
+      */
+     protected $listenerProvider;
+ 
+-    public function __construct(ListenerProviderInterface $listenerProvider = null)
++    public function __construct(?ListenerProviderInterface $listenerProvider = null)
+     {
+         $this->listenerProvider = $listenerProvider instanceof ListenerProviderInterface
+             ? $listenerProvider
diff --git a/tools/patches/league-oauth2-client-php84.patch b/tools/patches/league-oauth2-client-php84.patch
new file mode 100644
index 00000000000..772afef7158
--- /dev/null
+++ b/tools/patches/league-oauth2-client-php84.patch
@@ -0,0 +1,13 @@
+diff --git a/src/Provider/AbstractProvider.php b/src/Provider/AbstractProvider.php
+index 293a54d6..feba9559 100644
+--- a/src/Provider/AbstractProvider.php
++++ b/src/Provider/AbstractProvider.php
+@@ -495,7 +495,7 @@ public function getAuthorizationUrl(array $options = [])
+      */
+     public function authorize(
+         array $options = [],
+-        callable $redirectHandler = null
++        ?callable $redirectHandler = null
+     ) {
+         $url = $this->getAuthorizationUrl($options);
+         if ($redirectHandler) {
diff --git a/tools/patches/league-oauth2-server-php84.patch b/tools/patches/league-oauth2-server-php84.patch
new file mode 100644
index 00000000000..ec60e61bf37
--- /dev/null
+++ b/tools/patches/league-oauth2-server-php84.patch
@@ -0,0 +1,114 @@
+diff --git a/src/Exception/OAuthServerException.php b/src/Exception/OAuthServerException.php
+index 9eff92456..24a38d3fe 100644
+--- a/src/Exception/OAuthServerException.php
++++ b/src/Exception/OAuthServerException.php
+@@ -33,7 +33,7 @@ class OAuthServerException extends Exception
+     /**
+      * Throw a new exception.
+      */
+-    final public function __construct(string $message, int $code, private string $errorType, private int $httpStatusCode = 400, private ?string $hint = null, private ?string $redirectUri = null, Throwable $previous = null)
++    final public function __construct(string $message, int $code, private string $errorType, private int $httpStatusCode = 400, private ?string $hint = null, private ?string $redirectUri = null, ?Throwable $previous = null)
+     {
+         parent::__construct($message, $code, $previous);
+         $this->payload = [
+@@ -88,7 +88,7 @@ public static function unsupportedGrantType(): static
+     /**
+      * Invalid request error.
+      */
+-    public static function invalidRequest(string $parameter, ?string $hint = null, Throwable $previous = null): static
++    public static function invalidRequest(string $parameter, ?string $hint = null, ?Throwable $previous = null): static
+     {
+         $errorMessage = 'The request is missing a required parameter, includes an invalid parameter value, ' .
+             'includes a parameter more than once, or is otherwise malformed.';
+@@ -141,7 +141,7 @@ public static function invalidCredentials(): static
+      *
+      * @codeCoverageIgnore
+      */
+-    public static function serverError(string $hint, Throwable $previous = null): static
++    public static function serverError(string $hint, ?Throwable $previous = null): static
+     {
+         return new static(
+             'The authorization server encountered an unexpected condition which prevented it from fulfilling'
+@@ -158,7 +158,7 @@ public static function serverError(string $hint, Throwable $previous = null): st
+     /**
+      * Invalid refresh token.
+      */
+-    public static function invalidRefreshToken(?string $hint = null, Throwable $previous = null): static
++    public static function invalidRefreshToken(?string $hint = null, ?Throwable $previous = null): static
+     {
+         return new static('The refresh token is invalid.', 8, 'invalid_grant', 400, $hint, null, $previous);
+     }
+@@ -166,7 +166,7 @@ public static function invalidRefreshToken(?string $hint = null, Throwable $prev
+     /**
+      * Access denied.
+      */
+-    public static function accessDenied(?string $hint = null, ?string $redirectUri = null, Throwable $previous = null): static
++    public static function accessDenied(?string $hint = null, ?string $redirectUri = null, ?Throwable $previous = null): static
+     {
+         return new static(
+             'The resource owner or authorization server denied the request.',
+@@ -207,7 +207,7 @@ public function getErrorType(): string
+      *
+      * @return static
+      */
+-    public static function expiredToken(?string $hint = null, Throwable $previous = null): static
++    public static function expiredToken(?string $hint = null, ?Throwable $previous = null): static
+     {
+         $errorMessage = 'The `device_code` has expired and the device ' .
+                         'authorization session has concluded.';
+@@ -215,7 +215,7 @@ public static function expiredToken(?string $hint = null, Throwable $previous =
+         return new static($errorMessage, 11, 'expired_token', 400, $hint, null, $previous);
+     }
+ 
+-    public static function authorizationPending(string $hint = '', Throwable $previous = null): static
++    public static function authorizationPending(string $hint = '', ?Throwable $previous = null): static
+     {
+         return new static(
+             'The authorization request is still pending as the end user ' .
+@@ -236,7 +236,7 @@ public static function authorizationPending(string $hint = '', Throwable $previo
+      *
+      * @return static
+      */
+-    public static function slowDown(string $hint = '', Throwable $previous = null): static
++    public static function slowDown(string $hint = '', ?Throwable $previous = null): static
+     {
+         return new static(
+             'The authorization request is still pending and polling should ' .
+diff --git a/src/Grant/AbstractGrant.php b/src/Grant/AbstractGrant.php
+index ea0064c3b..5ab81ff77 100644
+--- a/src/Grant/AbstractGrant.php
++++ b/src/Grant/AbstractGrant.php
+@@ -243,7 +243,7 @@ protected function validateRedirectUri(
+      *
+      * @return ScopeEntityInterface[]
+      */
+-    public function validateScopes(string|array|null $scopes, string $redirectUri = null): array
++    public function validateScopes(string|array|null $scopes, ?string $redirectUri = null): array
+     {
+         if ($scopes === null) {
+             $scopes = [];
+diff --git a/src/ResourceServer.php b/src/ResourceServer.php
+index e89e8d24a..102466fd6 100644
+--- a/src/ResourceServer.php
++++ b/src/ResourceServer.php
+@@ -22,19 +22,15 @@ class ResourceServer
+ {
+     private CryptKeyInterface $publicKey;
+ 
+-    private ?AuthorizationValidatorInterface $authorizationValidator = null;
+-
+     public function __construct(
+         private AccessTokenRepositoryInterface $accessTokenRepository,
+         CryptKeyInterface|string $publicKey,
+-        AuthorizationValidatorInterface $authorizationValidator = null
++        private ?AuthorizationValidatorInterface $authorizationValidator = null
+     ) {
+         if ($publicKey instanceof CryptKeyInterface === false) {
+             $publicKey = new CryptKey($publicKey);
+         }
+         $this->publicKey = $publicKey;
+-
+-        $this->authorizationValidator = $authorizationValidator;
+     }
+ 
+     protected function getAuthorizationValidator(): AuthorizationValidatorInterface
diff --git a/tools/patches/sabre-dav-php84.patch b/tools/patches/sabre-dav-php84.patch
new file mode 100644
index 00000000000..e25f5f30c46
--- /dev/null
+++ b/tools/patches/sabre-dav-php84.patch
@@ -0,0 +1,74 @@
+diff --git a/lib/CardDAV/Plugin.php b/lib/CardDAV/Plugin.php
+index c2d31d9dfe..810ae3a1ab 100644
+--- a/lib/CardDAV/Plugin.php
++++ b/lib/CardDAV/Plugin.php
+@@ -800,7 +800,7 @@ protected function negotiateVCard($input, &$mimeType = null)
+      *
+      * @return string
+      */
+-    protected function convertVCard($data, $target, array $propertiesFilter = null)
++    protected function convertVCard($data, $target, ?array $propertiesFilter = null)
+     {
+         if (is_resource($data)) {
+             $data = stream_get_contents($data);
+diff --git a/lib/CardDAV/Xml/Property/SupportedAddressData.php b/lib/CardDAV/Xml/Property/SupportedAddressData.php
+index fe5f976a03..536c5a19fc 100644
+--- a/lib/CardDAV/Xml/Property/SupportedAddressData.php
++++ b/lib/CardDAV/Xml/Property/SupportedAddressData.php
+@@ -34,7 +34,7 @@ class SupportedAddressData implements XmlSerializable
+     /**
+      * Creates the property.
+      */
+-    public function __construct(array $supportedData = null)
++    public function __construct(?array $supportedData = null)
+     {
+         if (is_null($supportedData)) {
+             $supportedData = [
+diff --git a/lib/DAV/Auth/Plugin.php b/lib/DAV/Auth/Plugin.php
+index eb4f27ca67..47fbe205ac 100644
+--- a/lib/DAV/Auth/Plugin.php
++++ b/lib/DAV/Auth/Plugin.php
+@@ -58,7 +58,7 @@ class Plugin extends ServerPlugin
+      *
+      * @param Backend\BackendInterface $authBackend
+      */
+-    public function __construct(Backend\BackendInterface $authBackend = null)
++    public function __construct(?Backend\BackendInterface $authBackend = null)
+     {
+         if (!is_null($authBackend)) {
+             $this->addBackend($authBackend);
+diff --git a/lib/DAV/Exception/Locked.php b/lib/DAV/Exception/Locked.php
+index 28263cf13e..24fad70955 100644
+--- a/lib/DAV/Exception/Locked.php
++++ b/lib/DAV/Exception/Locked.php
+@@ -32,7 +32,7 @@ class Locked extends DAV\Exception
+      *
+      * @param DAV\Locks\LockInfo $lock
+      */
+-    public function __construct(DAV\Locks\LockInfo $lock = null)
++    public function __construct(?DAV\Locks\LockInfo $lock = null)
+     {
+         parent::__construct();
+ 
+diff --git a/lib/DAV/Server.php b/lib/DAV/Server.php
+index 1a97951ecd..3133e54ad3 100644
+--- a/lib/DAV/Server.php
++++ b/lib/DAV/Server.php
+@@ -211,7 +211,7 @@ class Server implements LoggerAwareInterface, EmitterInterface
+      *
+      * @throws Exception
+      */
+-    public function __construct($treeOrNode = null, HTTP\Sapi $sapi = null)
++    public function __construct($treeOrNode = null, ?HTTP\Sapi $sapi = null)
+     {
+         if ($treeOrNode instanceof Tree) {
+             $this->tree = $treeOrNode;
+@@ -882,7 +882,7 @@ public function getHTTPHeaders($path)
+      *
+      * @return \Traversable
+      */
+-    private function generatePathNodes(PropFind $propFind, array $yieldFirst = null)
++    private function generatePathNodes(PropFind $propFind, ?array $yieldFirst = null)
+     {
+         if (null !== $yieldFirst) {
+             yield $yieldFirst;
diff --git a/tools/patches/sabre-vobject-php84.patch b/tools/patches/sabre-vobject-php84.patch
new file mode 100644
index 00000000000..82f785b65c1
--- /dev/null
+++ b/tools/patches/sabre-vobject-php84.patch
@@ -0,0 +1,198 @@
+diff --git a/lib/Component/VCalendar.php b/lib/Component/VCalendar.php
+index 4db318135..017aed70c 100644
+--- a/lib/Component/VCalendar.php
++++ b/lib/Component/VCalendar.php
+@@ -281,7 +281,7 @@ public function getBaseComponent($componentName = null)
+      *
+      * @return VCalendar
+      */
+-    public function expand(DateTimeInterface $start, DateTimeInterface $end, DateTimeZone $timeZone = null)
++    public function expand(DateTimeInterface $start, DateTimeInterface $end, ?DateTimeZone $timeZone = null)
+     {
+         $newChildren = [];
+         $recurringEvents = [];
+diff --git a/lib/DateTimeParser.php b/lib/DateTimeParser.php
+index c5dbac97d..69072ef8c 100644
+--- a/lib/DateTimeParser.php
++++ b/lib/DateTimeParser.php
+@@ -31,7 +31,7 @@ class DateTimeParser
+      *
+      * @return DateTimeImmutable
+      */
+-    public static function parseDateTime($dt, DateTimeZone $tz = null)
++    public static function parseDateTime($dt, ?DateTimeZone $tz = null)
+     {
+         // Format is YYYYMMDD + "T" + hhmmss
+         $result = preg_match('/^([0-9]{4})([0-1][0-9])([0-3][0-9])T([0-2][0-9])([0-5][0-9])([0-5][0-9])([Z]?)$/', $dt, $matches);
+@@ -61,7 +61,7 @@ public static function parseDateTime($dt, DateTimeZone $tz = null)
+      *
+      * @return DateTimeImmutable
+      */
+-    public static function parseDate($date, DateTimeZone $tz = null)
++    public static function parseDate($date, ?DateTimeZone $tz = null)
+     {
+         // Format is YYYYMMDD
+         $result = preg_match('/^([0-9]{4})([0-1][0-9])([0-3][0-9])$/', $date, $matches);
+diff --git a/lib/Document.php b/lib/Document.php
+index 6b908c70e..d2131f479 100644
+--- a/lib/Document.php
++++ b/lib/Document.php
+@@ -157,7 +157,7 @@ public function create($name)
+      *
+      * @return Component
+      */
+-    public function createComponent($name, array $children = null, $defaults = true)
++    public function createComponent($name, ?array $children = null, $defaults = true)
+     {
+         $name = strtoupper($name);
+         $class = Component::class;
+@@ -187,7 +187,7 @@ public function createComponent($name, array $children = null, $defaults = true)
+      * @param array  $parameters
+      * @param string $valueType  Force a specific valuetype, such as URI or TEXT
+      */
+-    public function createProperty($name, $value = null, array $parameters = null, $valueType = null, int $lineIndex = null, string $lineString = null): Property
++    public function createProperty($name, $value = null, ?array $parameters = null, $valueType = null, ?int $lineIndex = null, ?string $lineString = null): Property
+     {
+         // If there's a . in the name, it means it's prefixed by a groupname.
+         if (false !== ($i = strpos($name, '.'))) {
+diff --git a/lib/FreeBusyGenerator.php b/lib/FreeBusyGenerator.php
+index 81b8126d5..56ae166fa 100644
+--- a/lib/FreeBusyGenerator.php
++++ b/lib/FreeBusyGenerator.php
+@@ -89,7 +89,7 @@ class FreeBusyGenerator
+      * @param mixed             $objects
+      * @param DateTimeZone      $timeZone
+      */
+-    public function __construct(DateTimeInterface $start = null, DateTimeInterface $end = null, $objects = null, DateTimeZone $timeZone = null)
++    public function __construct(?DateTimeInterface $start = null, ?DateTimeInterface $end = null, $objects = null, ?DateTimeZone $timeZone = null)
+     {
+         $this->setTimeRange($start, $end);
+ 
+@@ -158,7 +158,7 @@ public function setObjects($objects)
+      * @param DateTimeInterface $start
+      * @param DateTimeInterface $end
+      */
+-    public function setTimeRange(DateTimeInterface $start = null, DateTimeInterface $end = null)
++    public function setTimeRange(?DateTimeInterface $start = null, ?DateTimeInterface $end = null)
+     {
+         if (!$start) {
+             $start = new DateTimeImmutable(Settings::$minDate);
+diff --git a/lib/ITip/Broker.php b/lib/ITip/Broker.php
+index dbdd80b78..f007304ce 100644
+--- a/lib/ITip/Broker.php
++++ b/lib/ITip/Broker.php
+@@ -108,7 +108,7 @@ class Broker
+      *
+      * @return VCalendar|null
+      */
+-    public function processMessage(Message $itipMessage, VCalendar $existingObject = null)
++    public function processMessage(Message $itipMessage, ?VCalendar $existingObject = null)
+     {
+         // We only support events at the moment.
+         if ('VEVENT' !== $itipMessage->component) {
+@@ -266,7 +266,7 @@ public function parseEvent($calendar, $userHref, $oldCalendar = null)
+      *
+      * @return VCalendar|null
+      */
+-    protected function processMessageRequest(Message $itipMessage, VCalendar $existingObject = null)
++    protected function processMessageRequest(Message $itipMessage, ?VCalendar $existingObject = null)
+     {
+         if (!$existingObject) {
+             // This is a new invite, and we're just going to copy over
+@@ -301,7 +301,7 @@ protected function processMessageRequest(Message $itipMessage, VCalendar $existi
+      *
+      * @return VCalendar|null
+      */
+-    protected function processMessageCancel(Message $itipMessage, VCalendar $existingObject = null)
++    protected function processMessageCancel(Message $itipMessage, ?VCalendar $existingObject = null)
+     {
+         if (!$existingObject) {
+             // The event didn't exist in the first place, so we're just
+@@ -326,7 +326,7 @@ protected function processMessageCancel(Message $itipMessage, VCalendar $existin
+      *
+      * @return VCalendar|null
+      */
+-    protected function processMessageReply(Message $itipMessage, VCalendar $existingObject = null)
++    protected function processMessageReply(Message $itipMessage, ?VCalendar $existingObject = null)
+     {
+         // A reply can only be processed based on an existing object.
+         // If the object is not available, the reply is ignored.
+@@ -807,7 +807,7 @@ protected function parseEventForAttendee(VCalendar $calendar, array $eventInfo,
+      *
+      * @return array
+      */
+-    protected function parseEventInfo(VCalendar $calendar = null)
++    protected function parseEventInfo(?VCalendar $calendar = null)
+     {
+         $uid = null;
+         $organizer = null;
+diff --git a/lib/Property.php b/lib/Property.php
+index 0805c139a..f52760f9c 100644
+--- a/lib/Property.php
++++ b/lib/Property.php
+@@ -81,7 +81,7 @@ abstract class Property extends Node
+      * @param array             $parameters List of parameters
+      * @param string            $group      The vcard property group
+      */
+-    public function __construct(Component $root, $name, $value = null, array $parameters = [], $group = null, int $lineIndex = null, string $lineString = null)
++    public function __construct(Component $root, $name, $value = null, array $parameters = [], $group = null, ?int $lineIndex = null, ?string $lineString = null)
+     {
+         $this->name = $name;
+         $this->group = $group;
+diff --git a/lib/Property/ICalendar/DateTime.php b/lib/Property/ICalendar/DateTime.php
+index ca71633b9..3ea21e2ec 100644
+--- a/lib/Property/ICalendar/DateTime.php
++++ b/lib/Property/ICalendar/DateTime.php
+@@ -131,7 +131,7 @@ public function isFloating()
+      *
+      * @return \DateTimeImmutable
+      */
+-    public function getDateTime(DateTimeZone $timeZone = null)
++    public function getDateTime(?DateTimeZone $timeZone = null)
+     {
+         $dt = $this->getDateTimes($timeZone);
+         if (!$dt) {
+@@ -153,7 +153,7 @@ public function getDateTime(DateTimeZone $timeZone = null)
+      * @return \DateTimeImmutable[]
+      * @return \DateTime[]
+      */
+-    public function getDateTimes(DateTimeZone $timeZone = null)
++    public function getDateTimes(?DateTimeZone $timeZone = null)
+     {
+         // Does the property have a TZID?
+         $tzid = $this['TZID'];
+diff --git a/lib/Recur/EventIterator.php b/lib/Recur/EventIterator.php
+index 61f05d7de..55d6e4779 100644
+--- a/lib/Recur/EventIterator.php
++++ b/lib/Recur/EventIterator.php
+@@ -93,7 +93,7 @@ class EventIterator implements \Iterator
+      * @param DateTimeZone    $timeZone reference timezone for floating dates and
+      *                                  times
+      */
+-    public function __construct($input, $uid = null, DateTimeZone $timeZone = null)
++    public function __construct($input, $uid = null, ?DateTimeZone $timeZone = null)
+     {
+         if (is_null($timeZone)) {
+             $timeZone = new DateTimeZone('UTC');
+diff --git a/lib/TimeZoneUtil.php b/lib/TimeZoneUtil.php
+index 6422c0930..0d77e71ed 100644
+--- a/lib/TimeZoneUtil.php
++++ b/lib/TimeZoneUtil.php
+@@ -75,7 +75,7 @@ private function addFinder(string $key, TimezoneFinder $finder): void
+      * Alternatively, if $failIfUncertain is set to true, it will throw an
+      * exception if we cannot accurately determine the timezone.
+      */
+-    private function findTimeZone(string $tzid, Component $vcalendar = null, bool $failIfUncertain = false): DateTimeZone
++    private function findTimeZone(string $tzid, ?Component $vcalendar = null, bool $failIfUncertain = false): DateTimeZone
+     {
+         foreach ($this->timezoneFinders as $timezoneFinder) {
+             $timezone = $timezoneFinder->find($tzid, $failIfUncertain);
+@@ -126,7 +126,7 @@ public static function addTimezoneFinder(string $key, TimezoneFinder $finder): v
+      *
+      * @return DateTimeZone
+      */
+-    public static function getTimeZone($tzid, Component $vcalendar = null, $failIfUncertain = false)
++    public static function getTimeZone($tzid, ?Component $vcalendar = null, $failIfUncertain = false)
+     {
+         return self::getInstance()->findTimeZone($tzid, $vcalendar, $failIfUncertain);
+     }
diff --git a/tools/patches/swaggest-json-diff-php84.patch b/tools/patches/swaggest-json-diff-php84.patch
new file mode 100644
index 00000000000..73fa7996f25
--- /dev/null
+++ b/tools/patches/swaggest-json-diff-php84.patch
@@ -0,0 +1,65 @@
+diff --git a/src/InvalidFieldTypeException.php b/src/InvalidFieldTypeException.php
+index d807046..37b45bc 100644
+--- a/src/InvalidFieldTypeException.php
++++ b/src/InvalidFieldTypeException.php
+@@ -27,7 +27,7 @@ public function __construct(
+         $expectedType,
+         $operation,
+         $code = 0,
+-        Throwable $previous = null
++        ?Throwable $previous = null
+     )
+     {
+         parent::__construct(
+diff --git a/src/MissingFieldException.php b/src/MissingFieldException.php
+index ab87967..d9e746e 100644
+--- a/src/MissingFieldException.php
++++ b/src/MissingFieldException.php
+@@ -22,7 +22,7 @@ public function __construct(
+         $missingField,
+         $operation,
+         $code = 0,
+-        Throwable $previous = null
++        ?Throwable $previous = null
+     )
+     {
+         parent::__construct('Missing "' . $missingField . '" in operation data', $code, $previous);
+diff --git a/src/PatchTestOperationFailedException.php b/src/PatchTestOperationFailedException.php
+index 7204b7c..d668110 100644
+--- a/src/PatchTestOperationFailedException.php
++++ b/src/PatchTestOperationFailedException.php
+@@ -23,7 +23,7 @@ public function __construct(
+         $operation,
+         $actualValue,
+         $code = 0,
+-        Throwable $previous = null
++        ?Throwable $previous = null
+     )
+     {
+         parent::__construct('Test operation ' . json_encode($operation, JSON_UNESCAPED_SLASHES)
+diff --git a/src/PathException.php b/src/PathException.php
+index 6d54fe4..2f2d6d4 100644
+--- a/src/PathException.php
++++ b/src/PathException.php
+@@ -29,7 +29,7 @@ public function __construct(
+         $operation,
+         $field,
+         $code = 0,
+-        Throwable $previous = null
++        ?Throwable $previous = null
+     )
+     {
+         parent::__construct($message, $code, $previous);
+diff --git a/src/UnknownOperationException.php b/src/UnknownOperationException.php
+index 8d35abb..c0357b7 100644
+--- a/src/UnknownOperationException.php
++++ b/src/UnknownOperationException.php
+@@ -19,7 +19,7 @@ class UnknownOperationException extends Exception
+     public function __construct(
+         $operation,
+         $code = 0,
+-        Throwable $previous = null
++        ?Throwable $previous = null
+     )
+     {
+         // @phpstan-ignore-next-line MissingFieldOperation will be thrown if op is not set
diff --git a/tools/patches/swaggest-json-schema-php84.patch b/tools/patches/swaggest-json-schema-php84.patch
new file mode 100644
index 00000000000..9a3e5eae980
--- /dev/null
+++ b/tools/patches/swaggest-json-schema-php84.patch
@@ -0,0 +1,159 @@
+diff --git a/src/Context.php b/src/Context.php
+index c655dde..fff2862 100644
+--- a/src/Context.php
++++ b/src/Context.php
+@@ -75,7 +75,7 @@ public function setSkipValidation($skipValidation = true)
+      * ProcessingOptions constructor.
+      * @param RemoteRefProvider $remoteRefProvider
+      */
+-    public function __construct(RemoteRefProvider $remoteRefProvider = null)
++    public function __construct(?RemoteRefProvider $remoteRefProvider = null)
+     {
+         $this->remoteRefProvider = $remoteRefProvider;
+     }
+diff --git a/src/RemoteRef/Preloaded.php b/src/RemoteRef/Preloaded.php
+index e5b4a38..dc92937 100644
+--- a/src/RemoteRef/Preloaded.php
++++ b/src/RemoteRef/Preloaded.php
+@@ -42,7 +42,7 @@ public function getSchemaData($url)
+      * @param Context|null $options
+      * @throws \Swaggest\JsonSchema\Exception
+      */
+-    public function populateSchemas(RefResolver $refResolver, Context $options = null)
++    public function populateSchemas(RefResolver $refResolver, ?Context $options = null)
+     {
+         if ($options === null) {
+             $options = new Context();
+diff --git a/src/Schema.php b/src/Schema.php
+index 6c1cee8..ff07f0c 100644
+--- a/src/Schema.php
++++ b/src/Schema.php
+@@ -109,7 +109,7 @@ public function addPropertyMapping($dataName, $propertyName, $mapping = self::DE
+      * @throws InvalidValue
+      * @throws \Exception
+      */
+-    public static function import($data, Context $options = null)
++    public static function import($data, ?Context $options = null)
+     {
+         if (null === $options) {
+             $options = new Context();
+@@ -148,7 +148,7 @@ public static function import($data, Context $options = null)
+      * @throws InvalidValue
+      * @throws \Exception
+      */
+-    public function in($data, Context $options = null)
++    public function in($data, ?Context $options = null)
+     {
+         if (null !== $this->__booleanSchema) {
+             if ($this->__booleanSchema) {
+@@ -187,7 +187,7 @@ public function in($data, Context $options = null)
+      * @throws InvalidValue
+      * @throws \Exception
+      */
+-    public function out($data, Context $options = null)
++    public function out($data, ?Context $options = null)
+     {
+         if ($options === null) {
+             $options = new Context();
+@@ -1385,7 +1385,7 @@ public function getMeta($name)
+      * @param Context $options
+      * @return ObjectItemContract
+      */
+-    public function makeObjectItem(Context $options = null)
++    public function makeObjectItem(?Context $options = null)
+     {
+         if (null === $this->objectItemClass) {
+             return new ObjectItem();
+diff --git a/src/SchemaContract.php b/src/SchemaContract.php
+index a051305..bff1363 100644
+--- a/src/SchemaContract.php
++++ b/src/SchemaContract.php
+@@ -22,7 +22,7 @@ public function process($data, Context $options, $path = '#', $result = null);
+      * @throws InvalidValue
+      * @return array|mixed|null|object|\stdClass
+      */
+-    public function in($data, Context $options = null);
++    public function in($data, ?Context $options = null);
+ 
+     /**
+      * @param mixed $data
+@@ -30,7 +30,7 @@ public function in($data, Context $options = null);
+      * @throws InvalidValue
+      * @return array|mixed|null|object|\stdClass
+      */
+-    public function out($data, Context $options = null);
++    public function out($data, ?Context $options = null);
+ 
+     /**
+      * @return mixed
+@@ -44,7 +44,7 @@ public function getProperties();
+      * @param Context|null $options
+      * @return Structure\ObjectItemContract
+      */
+-    public function makeObjectItem(Context $options = null);
++    public function makeObjectItem(?Context $options = null);
+ 
+     /**
+      * @return string
+diff --git a/src/Structure/ClassStructureTrait.php b/src/Structure/ClassStructureTrait.php
+index c0bb6fc..393e65b 100644
+--- a/src/Structure/ClassStructureTrait.php
++++ b/src/Structure/ClassStructureTrait.php
+@@ -55,7 +55,7 @@ public static function properties()
+      * @throws \Swaggest\JsonSchema\Exception
+      * @throws \Swaggest\JsonSchema\InvalidValue
+      */
+-    public static function import($data, Context $options = null)
++    public static function import($data, ?Context $options = null)
+     {
+         return static::schema()->in($data, $options);
+     }
+@@ -67,7 +67,7 @@ public static function import($data, Context $options = null)
+      * @throws \Swaggest\JsonSchema\InvalidValue
+      * @throws \Exception
+      */
+-    public static function export($data, Context $options = null)
++    public static function export($data, ?Context $options = null)
+     {
+         return static::schema()->out($data, $options);
+     }
+@@ -150,7 +150,7 @@ public function jsonSerialize()
+     /**
+      * @return static|NameMirror
+      */
+-    public static function names(Properties $properties = null, $mapping = Schema::DEFAULT_MAPPING)
++    public static function names(?Properties $properties = null, $mapping = Schema::DEFAULT_MAPPING)
+     {
+         if ($properties !== null) {
+             return new NameMirror($properties->getDataKeyMap($mapping));
+diff --git a/src/Wrapper.php b/src/Wrapper.php
+index 98946f6..421ec12 100644
+--- a/src/Wrapper.php
++++ b/src/Wrapper.php
+@@ -53,7 +53,7 @@ public function process($data, Context $options, $path = '#', $result = null)
+      * @throws Exception
+      * @throws InvalidValue
+      */
+-    public function in($data, Context $options = null)
++    public function in($data, ?Context $options = null)
+     {
+         return $this->schema->in($data, $options);
+     }
+@@ -65,7 +65,7 @@ public function in($data, Context $options = null)
+      * @throws InvalidValue
+      * @throws \Exception
+      */
+-    public function out($data, Context $options = null)
++    public function out($data, ?Context $options = null)
+     {
+         return $this->schema->out($data, $options);
+     }
+@@ -199,7 +199,7 @@ public function getMeta($name)
+      * @param Context|null $options
+      * @return Structure\ObjectItemContract
+      */
+-    public function makeObjectItem(Context $options = null)
++    public function makeObjectItem(?Context $options = null)
+     {
+         return $this->schema->makeObjectItem($options);
+     }
diff --git a/tools/patches/symfony-cache-php84.patch b/tools/patches/symfony-cache-php84.patch
new file mode 100644
index 00000000000..0d07c6da99f
--- /dev/null
+++ b/tools/patches/symfony-cache-php84.patch
@@ -0,0 +1,35 @@
+diff --git a/Traits/Redis6ProxyTrait.php b/Traits/Redis6ProxyTrait.php
+index d339e560c7..34f60cb102 100644
+--- a/Traits/Redis6ProxyTrait.php
++++ b/Traits/Redis6ProxyTrait.php
+@@ -11,7 +11,7 @@
+ 
+ namespace Symfony\Component\Cache\Traits;
+ 
+-if (version_compare(phpversion('redis'), '6.1.0', '>=')) {
++if (version_compare(phpversion('redis'), '6.1.0-dev', '>=')) {
+     /**
+      * @internal
+      */
+@@ -27,7 +27,7 @@ if (version_compare(phpversion('redis'), '6.1.0', '>=')) {
+             return ($this->lazyObjectState->realInstance ??= ($this->lazyObjectState->initializer)())->hRandField(...\func_get_args());
+         }
+ 
+-        public function hSet($key, $fields_and_vals): \Redis|false|int
++        public function hSet($key, ...$fields_and_vals): \Redis|false|int
+         {
+             return ($this->lazyObjectState->realInstance ??= ($this->lazyObjectState->initializer)())->hSet(...\func_get_args());
+         }
+diff --git a/Traits/RedisCluster6ProxyTrait.php b/Traits/RedisCluster6ProxyTrait.php
+index 7addffb97c..9c3169e323 100644
+--- a/Traits/RedisCluster6ProxyTrait.php
++++ b/Traits/RedisCluster6ProxyTrait.php
+@@ -11,7 +11,7 @@
+ 
+ namespace Symfony\Component\Cache\Traits;
+ 
+-if (version_compare(phpversion('redis'), '6.1.0', '>')) {
++if (version_compare(phpversion('redis'), '6.1.0-dev', '>')) {
+     /**
+      * @internal
+      */
diff --git a/tools/patches/wapmorgan-unified-archive-php84.patch b/tools/patches/wapmorgan-unified-archive-php84.patch
new file mode 100644
index 00000000000..e0d95fee8fb
--- /dev/null
+++ b/tools/patches/wapmorgan-unified-archive-php84.patch
@@ -0,0 +1,13 @@
+diff --git a/src/Drivers/OneFile/OneFileDriver.php b/src/Drivers/OneFile/OneFileDriver.php
+index fee038b..96a1e00 100644
+--- a/src/Drivers/OneFile/OneFileDriver.php
++++ b/src/Drivers/OneFile/OneFileDriver.php
+@@ -110,7 +110,7 @@ public function getFileData($fileName)
+      * @return int
+      * @throws ArchiveExtractionException
+      */
+-    public function extractFiles($outputFolder, array $files = null)
++    public function extractFiles($outputFolder, ?array $files = null)
+     {
+         return $this->extractArchive($outputFolder);
+     }