diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index b597ef838d..3968ce0330 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php: [7.2, 7.3, 7.4]
+        php: [7.3, 7.4]
         dependency-version: [prefer-stable]
     steps:
       - name: Checkout code
diff --git a/composer.json b/composer.json
index f61497ef03..127d7e1bbc 100644
--- a/composer.json
+++ b/composer.json
@@ -55,7 +55,7 @@
     },
     "require-dev": {
         "php-coveralls/php-coveralls": "^2.2",
-        "phpunit/phpunit": "^8.0",
+        "phpunit/phpunit": "^9.2",
         "rregeer/phpunit-coverage-check": "^0.3.1",
         "friendsofphp/php-cs-fixer": "^2.16",
         "symfony/filesystem": "^5.0",
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 6ba5c3f035..1427f91661 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,22 +1,22 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="./vendor/phpunit/phpunit/phpunit.xsd"
-         bootstrap="vendor/autoload.php"
-         executionOrder="random"
-         resolveDependencies="true"
-         forceCoversAnnotation="true"
-         beStrictAboutCoversAnnotation="false"
-         colors="true">
-
-    <testsuites>
-        <testsuite name="PhpMimeMailParser Test Suite">
-            <directory>tests</directory>
-        </testsuite>
-    </testsuites>
-
-    <filter>
-        <whitelist addUncoveredFilesFromWhitelist="true">
-            <directory suffix=".php">src/</directory>
-        </whitelist>
-    </filter>
+<phpunit
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+  bootstrap="vendor/autoload.php"
+  executionOrder="random"
+  resolveDependencies="true"
+  forceCoversAnnotation="true"
+  beStrictAboutCoversAnnotation="false"
+  colors="true"
+>
+  <coverage includeUncoveredFiles="true">
+    <include>
+      <directory suffix=".php">src/</directory>
+    </include>
+  </coverage>
+  <testsuites>
+    <testsuite name="Unit">
+      <directory>tests</directory>
+    </testsuite>
+  </testsuites>
 </phpunit>
diff --git a/tests/AttachmentTest.php b/tests/AttachmentTest.php
index 18fd0bb003..e30de37dbc 100644
--- a/tests/AttachmentTest.php
+++ b/tests/AttachmentTest.php
@@ -118,7 +118,7 @@ public function testGeneratingDuplicateSuffixWithoutExtension(): void
         $this->assertFileExists($attachDir . 'attach02_3');
         $this->assertFileExists($attachDir . 'attach02_4');
         $this->assertFileExists($attachDir . 'attach02_5');
-        $this->assertFileNotExists($attachDir . 'attach02_6');
+        $this->assertFileDoesNotExist($attachDir . 'attach02_6');
     }
 
     public function testGeneratingDuplicateSuffix(): void
@@ -143,7 +143,7 @@ public function testGeneratingDuplicateSuffix(): void
         $this->assertFileExists($attachDir . 'logo_1.jpg');
         $this->assertFileExists($attachDir . 'logo_2.jpg');
         $this->assertFileExists($attachDir . 'logo_3.jpg');
-        $this->assertFileNotExists($attachDir . 'logo_4.jpg');
+        $this->assertFileDoesNotExist($attachDir . 'logo_4.jpg');
     }
 
     public function testSavingWithRandomFilenameKeepExtension(): void