diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0724232..55bbaa5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,7 +7,7 @@ on:
 jobs:
   PHPUnit:
     name: PHPUnit (PHP ${{ matrix.php }})
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
         php:
@@ -24,11 +24,12 @@ jobs:
           - 5.4
           - 5.3
     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
         if: ${{ matrix.php >= 7.3 }}
@@ -37,13 +38,16 @@ jobs:
 
   PHPUnit-hhvm:
     name: PHPUnit (HHVM)
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-22.04
     continue-on-error: true
     steps:
-      - uses: actions/checkout@v2
-      - uses: azjezz/setup-hhvm@v1
+      - uses: actions/checkout@v3
+      - run: cp "$(which composer)" composer.phar && ./composer.phar self-update --2.2 # downgrade Composer for HHVM
+      - name: Run hhvm composer.phar install
+        uses: docker://hhvm/hhvm:3.30-lts-latest
         with:
-          version: lts-3.30
-      - run: composer self-update --2.2 # downgrade Composer for HHVM
-      - run: hhvm $(which composer) install
-      - run: hhvm vendor/bin/phpunit
+          args: hhvm composer.phar install
+      - name: Run hhvm vendor/bin/phpunit
+        uses: docker://hhvm/hhvm:3.30-lts-latest
+        with:
+          args: hhvm vendor/bin/phpunit
diff --git a/composer.json b/composer.json
index ad0d9fe..153439a 100644
--- a/composer.json
+++ b/composer.json
@@ -29,13 +29,17 @@
         "php": ">=5.3.0",
         "react/promise": "^3.0 || ^2.0 || ^1.1"
     },
+    "require-dev": {
+        "phpunit/phpunit": "^9.5 || ^5.7 || ^4.8.35"
+    },
     "autoload": {
-        "psr-4": { "React\\Cache\\": "src/" }
+        "psr-4": {
+            "React\\Cache\\": "src/"
+        }
     },
     "autoload-dev": {
-        "psr-4": { "React\\Tests\\Cache\\": "tests/" }
-    },
-    "require-dev": {
-        "phpunit/phpunit": "^9.3 || ^5.7 || ^4.8.35"
+        "psr-4": {
+            "React\\Tests\\Cache\\": "tests/"
+        }
     }
 }
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index fa88e7e..7a9577e 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,11 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<!-- PHPUnit configuration file with new format for PHPUnit 9.3+ -->
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
-         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+<!-- PHPUnit configuration file with new format for PHPUnit 9.5+ -->
+<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>
@@ -16,4 +17,12 @@
             <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/phpunit.xml.legacy b/phpunit.xml.legacy
index fbb43e8..ac5600a 100644
--- a/phpunit.xml.legacy
+++ b/phpunit.xml.legacy
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<!-- PHPUnit configuration file with old format for PHPUnit 9.2 or older -->
+<!-- PHPUnit configuration file with old format for legacy PHPUnit -->
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/4.8/phpunit.xsd"
          bootstrap="vendor/autoload.php"
@@ -15,4 +15,12 @@
             <directory>./src/</directory>
         </whitelist>
     </filter>
+    <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>