diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..da20d18
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,7 @@
+/.gitattributes export-ignore
+/.github/workflows/ export-ignore
+/.gitignore export-ignore
+/examples/ export-ignore
+/phpunit.xml.dist export-ignore
+/phpunit.xml.legacy export-ignore
+/tests/ export-ignore
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cd3f079..38ed72e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,6 +10,9 @@ jobs:
     strategy:
       matrix:
         php:
+          - 8.0
+          - 7.4
+          - 7.3
           - 7.2
           - 7.1
           - 7.0
@@ -25,6 +28,9 @@ jobs:
           php-version: ${{ matrix.php }}
       - run: composer install
       - run: vendor/bin/phpunit --coverage-text
+        if: ${{ matrix.php >= 7.3 }}
+      - run: vendor/bin/phpunit --coverage-text -c phpunit.xml.legacy
+        if: ${{ matrix.php < 7.3 }}
 
   PHPUnit-hhvm:
     name: PHPUnit (HHVM)
@@ -34,6 +40,5 @@ jobs:
       - uses: azjezz/setup-hhvm@v1
         with:
           version: lts-3.30
-      - run: hhvm $(which composer) require phpunit/phpunit:^5 --dev --no-interaction # requires legacy phpunit
       - run: hhvm $(which composer) install
       - run: hhvm vendor/bin/phpunit
diff --git a/README.md b/README.md
index 9ea85c4..0a6d18f 100644
--- a/README.md
+++ b/README.md
@@ -234,7 +234,7 @@ $ composer require clue/arguments:^2.0
 See also the [CHANGELOG](CHANGELOG.md) for details about version upgrades.
 
 This project aims to run on any platform and thus does not require any PHP
-extensions and supports running on legacy PHP 5.3 through current PHP 7+ and
+extensions and supports running on legacy PHP 5.3 through current PHP 8+ and
 HHVM.
 It's *highly recommended to use PHP 7+* for this project.
 
diff --git a/composer.json b/composer.json
index 544ef7f..cecadbc 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
         "php": ">=5.3"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.0 || ^6.0 || ^5.7 || ^4.8.35"
+        "phpunit/phpunit": "^9.3 || ^5.7 || ^4.8.35"
     },
     "autoload": {
         "files": [ "src/functions.php" ],
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index a6e2430..dc332ca 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,14 +1,19 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<phpunit bootstrap="vendor/autoload.php" colors="true">
+<!-- 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"
+         bootstrap="vendor/autoload.php"
+         colors="true"
+         cacheResult="false">
     <testsuites>
-        <testsuite>
+        <testsuite name="Arguments test suite">
             <directory>./tests/</directory>
         </testsuite>
     </testsuites>
-    <filter>
-        <whitelist>
+    <coverage>
+        <include>
             <directory>./src/</directory>
-        </whitelist>
-    </filter>
+        </include>
+    </coverage>
 </phpunit>
diff --git a/phpunit.xml.legacy b/phpunit.xml.legacy
new file mode 100644
index 0000000..8000c04
--- /dev/null
+++ b/phpunit.xml.legacy
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!-- PHPUnit configuration file with old format for PHPUnit 9.2 or older -->
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/4.8/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         colors="true">
+    <testsuites>
+        <testsuite name="Arguments test suite">
+            <directory>./tests/</directory>
+        </testsuite>
+    </testsuites>
+    <filter>
+        <whitelist>
+            <directory>./src/</directory>
+        </whitelist>
+    </filter>
+</phpunit>
diff --git a/tests/SplitTest.php b/tests/SplitTest.php
index 76b7101..6b97da8 100644
--- a/tests/SplitTest.php
+++ b/tests/SplitTest.php
@@ -96,27 +96,21 @@ public function testSingleStringWithDoubleQuotesAndEscapedQuote()
         $this->assertEquals(array('he"llo'), $args);
     }
 
-    /**
-     * @expectedException Clue\Arguments\UnclosedQuotesException
-     */
     public function testSingleStringWithUnbalancedDoubleQuotesThrows()
     {
+        $this->setExpectedException('Clue\Arguments\UnclosedQuotesException');
         Arguments\split('"hello');
     }
 
-    /**
-     * @expectedException Clue\Arguments\UnclosedQuotesException
-     */
     public function testSingleStringWithUnbalancedSingleQuotesThrows()
     {
+        $this->setExpectedException('Clue\Arguments\UnclosedQuotesException');
         Arguments\split("'hello");
     }
 
-    /**
-     * @expectedException Clue\Arguments\UnclosedQuotesException
-     */
     public function testSimpleStringWithUnbalancedSingleQuotesThrows()
     {
+        $this->setExpectedException('Clue\Arguments\UnclosedQuotesException');
         Arguments\split("echo let's go");
     }
 
@@ -134,11 +128,9 @@ public function testDoubleQuotedWithAppendedString()
         $this->assertEquals(array('hello'), $args);
     }
 
-    /**
-     * @expectedException Clue\Arguments\UnclosedQuotesException
-     */
     public function testSimpleStringWithUnbalancedDoubleQuotesThrows()
     {
+        $this->setExpectedException('Clue\Arguments\UnclosedQuotesException');
         Arguments\split('hello "world');
     }
 
@@ -316,4 +308,21 @@ public function testSingleStringWithCombinedSingleQuotedPartsWithInterpretedEsca
 
         $this->assertEquals(array("\n\\n\n"), $args);
     }
+
+    public function setExpectedException($exception, $exceptionMessage = '', $exceptionCode = null)
+    {
+        if (method_exists($this, 'expectException')) {
+            // PHPUnit 5.2+
+            $this->expectException($exception);
+            if ($exceptionMessage !== '') {
+                $this->expectExceptionMessage($exceptionMessage);
+            }
+            if ($exceptionCode !== null) {
+                $this->expectExceptionCode($exceptionCode);
+            }
+        } else {
+            // legacy PHPUnit 4 - PHPUnit 5.1
+            parent::setExpectedException($exception, $exceptionMessage, $exceptionCode);
+        }
+    }
 }