diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6ea76507..71802ddf 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:
@@ -19,11 +19,12 @@ jobs:
           - 7.2
           - 7.1
     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
         if: ${{ matrix.php >= 7.3 }}
diff --git a/composer.json b/composer.json
index 2d532ede..b91ae987 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
         "php": ">=7.1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.3 || ^7.5"
+        "phpunit/phpunit": "^9.5 || ^7.5"
     },
     "autoload": {
         "psr-4": {
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 413f166a..42422782 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,8 +1,8 @@
 <?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"
@@ -22,5 +22,10 @@
     </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 a2a791a8..5a312e5d 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 before PHPUnit 9 -->
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/7.5/phpunit.xsd"
          bootstrap="vendor/autoload.php"
@@ -18,4 +18,12 @@
             </exclude>
         </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>