diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f3d940a..0e13e6f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,17 +7,18 @@ on:
 jobs:
   PHPUnit:
     name: PHPUnit (PHP ${{ matrix.php }})
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
         php:
           - 8.2
           - 8.1
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
           coverage: xdebug
+          ini-file: development
       - run: composer install
       - run: vendor/bin/phpunit --coverage-text
diff --git a/composer.json b/composer.json
index 8bdcd35..2d1ad50 100644
--- a/composer.json
+++ b/composer.json
@@ -31,7 +31,7 @@
         "react/promise": "^3.0 || ^2.8 || ^1.2.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.3"
+        "phpunit/phpunit": "^9.5"
     },
     "autoload": {
         "psr-4": {
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index f4b5805..63ec536 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,10 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
-         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.5/phpunit.xsd"
          bootstrap="vendor/autoload.php"
+         cacheResult="false"
          colors="true"
-         cacheResult="false">
+         convertDeprecationsToExceptions="true">
     <testsuites>
         <testsuite name="React Test Suite">
             <directory>./tests/</directory>
@@ -15,4 +16,12 @@
             <directory>./src/</directory>
         </include>
     </coverage>
+    <php>
+        <ini name="error_reporting" value="-1" />
+        <!-- Evaluate assertions, requires running with "php -d zend.assertions=1 vendor/bin/phpunit" -->
+        <!-- <ini name="zend.assertions=1" value="1" /> -->
+        <ini name="assert.active" value="1" />
+        <ini name="assert.exception" value="1" />
+        <ini name="assert.bail" value="0" />
+    </php>
 </phpunit>
diff --git a/tests/TestCase.php b/tests/TestCase.php
index ee0f476..904c63b 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -2,7 +2,6 @@
 
 namespace React\Tests\Async;
 
-use PHPUnit\Framework\MockObject\MockBuilder;
 use PHPUnit\Framework\TestCase as BaseTestCase;
 
 class TestCase extends BaseTestCase
@@ -40,12 +39,6 @@ protected function expectCallableNever()
 
     protected function createCallableMock()
     {
-        if (method_exists(MockBuilder::class, 'addMethods')) {
-            // PHPUnit 9+
-            return $this->getMockBuilder(\stdClass::class)->addMethods(['__invoke'])->getMock();
-        } else {
-            // PHPUnit < 9
-            return $this->getMockBuilder(\stdClass::class)->setMethods(['__invoke'])->getMock();
-        }
+        return $this->getMockBuilder(\stdClass::class)->addMethods(['__invoke'])->getMock();
     }
 }