diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2cc7f0ea..85aad9c5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,6 +11,7 @@ jobs:
     strategy:
       matrix:
         php:
+          - 8.3
           - 8.2
           - 8.1
           - 8.0
@@ -24,7 +25,7 @@ jobs:
           - 5.4
           - 5.3
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
@@ -45,7 +46,7 @@ jobs:
     runs-on: ubuntu-22.04
     continue-on-error: true
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: cp "$(which composer)" composer.phar && ./composer.phar self-update --2.2 # downgrade Composer for HHVM
       - name: Run hhvm composer.phar require --dev react/async:^2 react/promise:^2 phpunit/phpunit:^5.7 # downgrade Async and Promise for HHVM
         uses: docker://hhvm/hhvm:3.30-lts-latest
diff --git a/composer.json b/composer.json
index d50528c6..3f752a63 100644
--- a/composer.json
+++ b/composer.json
@@ -9,27 +9,20 @@
     },
     "require": {
         "php": ">=5.3.8",
-        "react/async": "^4 || ^3 || ^2",
+        "react/async": "^4.3 || ^3.2 || ^2.2",
         "react/cache": "^1.1",
-        "react/dns": "^1.11",
-        "react/event-loop": "^1.4",
-        "react/http": "^1.8",
-        "react/promise": "^3 || ^2.10 || ^1.2",
-        "react/promise-stream": "^1.6",
-        "react/promise-timer": "^1.9",
-        "react/socket": "^1.13",
-        "react/stream": "^1.3"
+        "react/dns": "^1.13",
+        "react/event-loop": "^1.5",
+        "react/http": "^1.11",
+        "react/promise": "^3.2 || ^2.10 || ^1.3",
+        "react/promise-stream": "^1.7",
+        "react/promise-timer": "^1.11",
+        "react/socket": "^1.15",
+        "react/stream": "^1.4"
     },
     "require-dev": {
         "clue/stream-filter": "^1.3",
-        "phpunit/phpunit": "^9.6 || ^7.5 || ^5.7 || ^4.8.36",
-        "react/async": "^4.2@dev || ^3.2@dev || ^4 || ^3 || ^2",
-        "react/dns": "^1.12@dev",
-        "react/http": "^1.10@dev",
-        "react/promise": "^3@dev || ^2.10 || ^1.2",
-        "react/promise-stream": "^1.7@dev",
-        "react/promise-timer": "^1.10@dev",
-        "react/socket": "^1.14@dev"
+        "phpunit/phpunit": "^9.6 || ^7.5 || ^5.7 || ^4.8.36"
     },
     "config": {
         "preferred-install": {
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index db5b8cac..2af732cf 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -2,7 +2,9 @@
 
 $autoload = require __DIR__ . '/../vendor/autoload.php';
 
-// register all `autoload-dev` paths from React's components
+assert($autoload instanceof Composer\Autoload\ClassLoader);
+
+// register all `autoload-dev` paths from ReactPHP's components
 foreach (glob(__DIR__ . '/../vendor/react/*/composer.json') as $b) {
     $config = json_decode(file_get_contents($b), true);
 
@@ -15,17 +17,3 @@
         }
     }
 }
-
-// load all legacy test bootstrap scripts from React's components
-foreach (glob(__DIR__ . '/../vendor/react/*/tests/bootstrap.php') as $b) {
-    // skip legacy react/promise for now and use manual autoload path from bootstrap config
-    // @link https://github.com/reactphp/promise/blob/1.x/tests/bootstrap.php
-    // @link https://github.com/reactphp/promise/blob/2.x/tests/bootstrap.php
-    if (strpos($b, 'react/promise/tests/bootstrap.php') !== false) {
-        $autoload->add('React\Promise', __DIR__ . '/../vendor/react/promise/tests');
-        $autoload->addPsr4('React\\Promise\\', __DIR__ . '/../vendor/react/promise/tests');
-        continue;
-    }
-
-    include $b;
-}