diff --git a/composer.json b/composer.json
index 38a2049..ef68ec2 100644
--- a/composer.json
+++ b/composer.json
@@ -31,8 +31,8 @@
         "mikey179/vfsstream": "^1.6.8",
         "inpsyde/php-coding-standards": "^1",
         "vimeo/psalm": "@stable",
-        "php-stubs/wordpress-stubs": ">=6.0@stable",
-        "johnpbloch/wordpress-core": ">=6.0"
+        "php-stubs/wordpress-stubs": ">=6.2@stable",
+        "johnpbloch/wordpress-core": ">=6.2"
     },
     "autoload": {
         "psr-4": {
@@ -45,8 +45,7 @@
     },
     "autoload-dev": {
         "psr-4": {
-            "Inpsyde\\Assets\\Tests\\Unit\\": "tests/phpunit/Unit/",
-            "Inpsyde\\Assets\\Tests\\Integration\\": "tests/phpunit/Integration/"
+            "Inpsyde\\Assets\\Tests\\Unit\\": "tests/phpunit/Unit/"
         }
     },
     "scripts": {
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 0ade292..5635080 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,5 +1,5 @@
 <?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" backupGlobals="false" backupStaticAttributes="false" bootstrap="tests/phpunit/bootstrap.php" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" processIsolation="false" stopOnFailure="false">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.6/phpunit.xsd" backupGlobals="false" backupStaticAttributes="false" bootstrap="tests/phpunit/bootstrap.php" colors="true" convertErrorsToExceptions="true" convertNoticesToExceptions="true" convertWarningsToExceptions="true" convertDeprecationsToExceptions="true" processIsolation="false" stopOnFailure="false">
   <coverage processUncoveredFiles="true">
     <include>
       <directory suffix=".php">src</directory>
@@ -14,7 +14,7 @@
   </coverage>
   <testsuites>
     <testsuite name="Unit">
-      <directory suffix="Test.php">tests/phpunit/Unit</directory>
+      <directory>tests/phpunit/Unit</directory>
     </testsuite>
   </testsuites>
   <logging/>
diff --git a/src/OutputFilter/AttributesOutputFilter.php b/src/OutputFilter/AttributesOutputFilter.php
index 8aec887..e2c995a 100644
--- a/src/OutputFilter/AttributesOutputFilter.php
+++ b/src/OutputFilter/AttributesOutputFilter.php
@@ -15,95 +15,34 @@
 
 use Inpsyde\Assets\Asset;
 
-/**
- * @psalm-suppress UndefinedMethod
- */
 class AttributesOutputFilter implements AssetOutputFilter
 {
-    private const ROOT_ELEMENT_START = '<root>';
-    private const ROOT_ELEMENT_END = '</root>';
-
-    /**
-     * @param string $html
-     * @param Asset $asset
-     *
-     * @return string
-     *
-     * phpcs:disable WordPress.PHP.NoSilencedErrors.Discouraged
-     * @psalm-suppress PossiblyFalseArgument
-     * @psalm-suppress ArgumentTypeCoercion
-     */
     public function __invoke(string $html, Asset $asset): string
     {
         $attributes = $asset->attributes();
-        if (count($attributes) === 0) {
+        if (!class_exists(\WP_HTML_Tag_Processor::class) || count($attributes) === 0) {
             return $html;
         }
 
-        $html = $this->wrapHtmlIntoRoot($html);
-
-        $doc = new \DOMDocument();
-        libxml_use_internal_errors(true);
-        @$doc->loadHTML(
-            mb_convert_encoding($html, 'HTML-ENTITIES', "UTF-8"),
-            LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD
-        );
-        libxml_clear_errors();
+        $tags = new \WP_HTML_Tag_Processor($html);
 
-        $scripts = $doc->getElementsByTagName('script');
-        foreach ($scripts as $script) {
-            // Only extend <script> elements with "src" attribute
-            // and don't extend inline <script></script> before and after.
-            if (!$script->hasAttribute('src')) {
-                continue;
-            }
-            $this->applyAttributes($script, $attributes);
+        // Only extend <script> elements with "src" attribute
+        // and don't extend inline <script></script> before and after.
+        if (
+            $tags->next_tag(['tag_name' => 'script'])
+            && (string) $tags->get_attribute('src')
+        ) {
+            $this->applyAttributes($tags, $attributes);
         }
 
-        return $this->removeRootElement($doc->saveHTML());
-    }
-
-    /**
-     * Wrapping multiple scripts into a root-element
-     * to be able to load it via DOMDocument.
-     *
-     * @param string $html
-     *
-     * @return string
-     */
-    protected function wrapHtmlIntoRoot(string $html): string
-    {
-        return self::ROOT_ELEMENT_START . $html . self::ROOT_ELEMENT_END;
-    }
-
-    /**
-     * Remove root element and return original HTML.
-     *
-     * @param string $html
-     *
-     * @return string
-     * @see AttributesOutputFilter::wrapHtmlIntoRoot()
-     *
-     */
-    protected function removeRootElement(string $html): string
-    {
-        $regex = '~' . self::ROOT_ELEMENT_START . '(.+?)' . self::ROOT_ELEMENT_END . '~s';
-        preg_match($regex, $html, $matches);
-
-        return $matches[1];
+        return $tags->get_updated_html();
     }
 
-    /**
-     * @param \DOMElement $script
-     * @param array $attributes
-     *
-     * @return void
-     */
-    protected function applyAttributes(\DOMElement $script, array $attributes)
+    protected function applyAttributes(\WP_HTML_Tag_Processor $script, array $attributes): void
     {
         foreach ($attributes as $key => $value) {
             $key = esc_attr((string) $key);
-            if ($script->hasAttribute($key)) {
+            if ((string) $script->get_attribute($key)) {
                 continue;
             }
             if (is_bool($value) && !$value) {
@@ -113,7 +52,7 @@ protected function applyAttributes(\DOMElement $script, array $attributes)
                 ? esc_attr($key)
                 : esc_attr((string) $value);
 
-            $script->setAttribute($key, $value);
+            $script->set_attribute($key, $value);
         }
     }
 }
diff --git a/tests/phpunit/Unit/OutputFilter/AttributesOutputFilterTest.php b/tests/phpunit/Unit/OutputFilter/AttributesOutputFilterTest.php
deleted file mode 100644
index c89ff98..0000000
--- a/tests/phpunit/Unit/OutputFilter/AttributesOutputFilterTest.php
+++ /dev/null
@@ -1,222 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-/*
- * This file is part of the Assets package.
- *
- * (c) Inpsyde GmbH
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Inpsyde\Assets\Tests\Unit\OutputFilter;
-
-use Inpsyde\Assets\Asset;
-use Inpsyde\Assets\OutputFilter\AssetOutputFilter;
-use Inpsyde\Assets\OutputFilter\AttributesOutputFilter;
-use Inpsyde\Assets\Tests\Unit\AbstractTestCase;
-
-use function Brain\Monkey\Functions\expect;
-
-class AttributesOutputFilterTest extends AbstractTestCase
-{
-    /**
-     * @test
-     */
-    public function testBasic()
-    {
-        $testee = new AttributesOutputFilter();
-
-        $stub = \Mockery::mock(Asset::class);
-        $stub->expects('attributes')->andReturn([]);
-
-        $input = '<script src="foo.js"></script>';
-
-        static::assertInstanceOf(AssetOutputFilter::class, $testee);
-        static::assertSame($input, $testee($input, $stub));
-    }
-
-    /**
-     * @param array $attributes
-     * @param array $expected
-     * @param array $notExpected
-     *
-     * @test
-     * @dataProvider provideAttributes
-     */
-    public function testRenderWithAttributes(array $attributes, array $expected, array $notExpected)
-    {
-        // esc_attr always returns a string, even if we input an integer.
-        expect('esc_attr')->andReturnUsing(
-            static function ($input): string {
-                return (string) $input;
-            }
-        );
-
-        $stub = \Mockery::mock(Asset::class);
-        $stub->expects('attributes')->andReturn($attributes);
-
-        $input = '<script src="script.js"></script>';
-
-        $testee = new AttributesOutputFilter();
-        $output = $testee($input, $stub);
-
-        foreach ($expected as $test) {
-            static::assertStringContainsString($test, $output);
-        }
-        foreach ($notExpected as $test) {
-            static::assertStringNotContainsString($test, $output);
-        }
-    }
-
-    /**
-     * @return \Generator
-     */
-    public function provideAttributes(): \Generator
-    {
-        yield 'string value' => [
-            [
-                'key' => 'value',
-            ],
-            ['key="value"'],
-            [],
-        ];
-
-        yield 'integer value' => [
-            [
-                'key' => 1,
-            ],
-            ['key="1"'],
-            [],
-        ];
-
-        yield 'bool true value' => [
-            [
-                'key' => true,
-            ],
-            ['key="key"'],
-            [],
-        ];
-
-        yield 'bool false value' => [
-            [
-                'key' => false,
-            ],
-            [],
-            ['key="key"'],
-        ];
-
-        yield 'overwriting src-attribute' => [
-            [
-                'key' => 'value',
-                'src' => 'not-allowed.js',
-            ],
-            ['key="value"'],
-            ['src="not-allowed.js"'],
-        ];
-    }
-
-    /**
-     * @test
-     */
-    public function testRenderNotOverwriteExistingAttributes()
-    {
-        $expectedKey = 'src';
-        $expectedValue = 'foo.js';
-        $expectedAttribute = sprintf('%s="%s"', $expectedKey, $expectedValue);
-
-        expect('esc_attr')->andReturnFirstArg();
-
-        $stub = \Mockery::mock(Asset::class);
-        // We're trying to overwrite the "src" with "bar.js".
-        $stub->expects('attributes')->andReturn([$expectedKey => 'bar.js']);
-
-        $input = sprintf('<script %s></script>', $expectedAttribute);
-
-        $testee = new AttributesOutputFilter();
-        static::assertStringContainsString($expectedAttribute, $testee($input, $stub));
-    }
-
-    /**
-     * @test
-     */
-    public function testRenderInlineScriptsNotChanged()
-    {
-        $expectedKey = 'key';
-        $expectedValue = 'value';
-        $expectedAttributes = [$expectedKey => $expectedValue];
-
-        $expectedBefore = "<script>var before = 'bar';</script>";
-        $expectedAfter = "<script>var after = 'bar';</script>";
-
-        expect('esc_attr')->andReturnFirstArg();
-
-        $stub = \Mockery::mock(Asset::class);
-        $stub->expects('attributes')->andReturn($expectedAttributes);
-
-        $input = $expectedBefore . '<script src="foo.js"></script>' . $expectedAfter;
-
-        $testee = new AttributesOutputFilter();
-        $output = $testee($input, $stub);
-        static::assertStringContainsString($expectedBefore, $output);
-        static::assertStringContainsString($expectedAfter, $output);
-    }
-
-    /**
-     * @param string $expectedBefore
-     * @param string $expectedAfter
-     *
-     * @test
-     * @dataProvider provideRenderWithInlineScripts
-     */
-    public function testRenderWithInlineScripts(string $expectedBefore, string $expectedAfter)
-    {
-        expect('esc_attr')->andReturnFirstArg();
-        $stub = \Mockery::mock(Asset::class);
-        $stub->expects('attributes')->andReturn(['foo' => 'bar']);
-
-        $input = $expectedBefore . '<script src="foo.js"></script>' . $expectedAfter;
-
-        $testee = new AttributesOutputFilter();
-        $output = $testee($input, $stub);
-        static::assertStringContainsString($expectedBefore, $output);
-        static::assertStringContainsString($expectedAfter, $output);
-    }
-
-    public function provideRenderWithInlineScripts(): \Generator
-    {
-        $singleLineJs = '(function(){ console.log("script with single line"); })();';
-        $multiLineJs = <<<JS
-(function() {
-    console.log("script with multiple lines")
-})();
-JS;
-
-        yield 'before single line' => [
-            $singleLineJs,
-            '',
-        ];
-
-        yield 'after single line' => [
-            '',
-            $singleLineJs,
-        ];
-
-        yield 'before and after single line' => [
-            $singleLineJs,
-            $singleLineJs,
-        ];
-
-        yield 'before multi, after single line' => [
-            $multiLineJs,
-            $singleLineJs,
-        ];
-
-        yield 'before and after multi line' => [
-            $multiLineJs,
-            $multiLineJs,
-        ];
-    }
-}