diff --git a/core/lib/Drupal/Core/Asset/CssCollectionRenderer.php b/core/lib/Drupal/Core/Asset/CssCollectionRenderer.php
index 24ea64ea7acc..13c53e24b4cf 100644
--- a/core/lib/Drupal/Core/Asset/CssCollectionRenderer.php
+++ b/core/lib/Drupal/Core/Asset/CssCollectionRenderer.php
@@ -72,6 +72,11 @@ class CssCollectionRenderer implements AssetCollectionRendererInterface {
           throw new \Exception('Invalid CSS asset type.');
       }
 
+      // Merge any additional attributes.
+      if (!empty($css_asset['attributes'])) {
+        $element['#attributes'] += $css_asset['attributes'];
+      }
+
       $elements[] = $element;
     }
 
diff --git a/core/tests/Drupal/Tests/Core/Asset/CssCollectionRendererUnitTest.php b/core/tests/Drupal/Tests/Core/Asset/CssCollectionRendererUnitTest.php
index b96f5eaa8647..39d65bfa4e9f 100644
--- a/core/tests/Drupal/Tests/Core/Asset/CssCollectionRendererUnitTest.php
+++ b/core/tests/Drupal/Tests/Core/Asset/CssCollectionRendererUnitTest.php
@@ -4,6 +4,7 @@ namespace Drupal\Tests\Core\Asset;
 
 use Drupal\Core\Asset\CssCollectionRenderer;
 use Drupal\Tests\UnitTestCase;
+use Drupal\Core\State\StateInterface;
 
 /**
  * Tests the CSS asset collection renderer.
@@ -27,18 +28,13 @@ class CssCollectionRendererUnitTest extends UnitTestCase {
   protected $fileCssGroup;
 
   /**
-   * The state mock class.
-   *
-   * @var \Drupal\Core\State\StateInterface|\PHPUnit\Framework\MockObject\MockObject
+   * {@inheritdoc}
    */
-  protected $state;
-
   protected function setUp(): void {
     parent::setUp();
-
-    $this->state = $this->createMock('Drupal\Core\State\StateInterface');
-
-    $this->renderer = new CssCollectionRenderer($this->state);
+    $state = $this->prophesize(StateInterface::class);
+    $state->get('system.css_js_query_string', '0')->shouldBeCalledOnce()->willReturn(NULL);
+    $this->renderer = new CssCollectionRenderer($state->reveal());
     $this->fileCssGroup = [
       'group' => -100,
       'type' => 'file',
@@ -76,15 +72,16 @@ class CssCollectionRendererUnitTest extends UnitTestCase {
    * @see testRender
    */
   public function providerTestRender() {
-    $create_link_element = function ($href, $media = 'all', $browsers = []) {
+    $create_link_element = function ($href, $media = 'all', $browsers = [], $custom_attributes = []) {
+      $attributes = [
+        'rel' => 'stylesheet',
+        'media' => $media,
+        'href' => $href,
+      ];
       return [
         '#type' => 'html_tag',
         '#tag' => 'link',
-        '#attributes' => [
-          'rel' => 'stylesheet',
-          'media' => $media,
-          'href' => $href,
-        ],
+        '#attributes' => array_replace($attributes, $custom_attributes),
         '#browsers' => $browsers,
       ];
     };
@@ -93,6 +90,8 @@ class CssCollectionRendererUnitTest extends UnitTestCase {
       return ['group' => 0, 'type' => 'file', 'media' => $media, 'preprocess' => $preprocess, 'data' => $data, 'browsers' => []];
     };
 
+    $custom_attributes = ['integrity' => 'sha384-psK1OYPAYjYUhtDYW+Pj2yc', 'crossorigin' => 'anonymous', 'random-attribute' => 'test'];
+
     return [
       // Single external CSS asset.
       0 => [
@@ -106,7 +105,7 @@ class CssCollectionRendererUnitTest extends UnitTestCase {
         ],
       ],
       // Single file CSS asset.
-      2 => [
+      1 => [
         [
           0 => ['group' => 0, 'type' => 'file', 'media' => 'all', 'preprocess' => TRUE, 'data' => 'public://css/file-all', 'browsers' => []],
         ],
@@ -114,6 +113,15 @@ class CssCollectionRendererUnitTest extends UnitTestCase {
           0 => $create_link_element(file_url_transform_relative(file_create_url('public://css/file-all')) . '?', 'all'),
         ],
       ],
+      // Single file CSS asset with custom attributes.
+      2 => [
+        [
+          0 => ['group' => 0, 'type' => 'file', 'media' => 'all', 'preprocess' => TRUE, 'data' => 'public://css/file-all', 'browsers' => [], 'attributes' => $custom_attributes],
+        ],
+        [
+          0 => $create_link_element(file_url_transform_relative(file_create_url('public://css/file-all')) . '?', 'all', [], $custom_attributes),
+        ],
+      ],
       // 31 file CSS assets: expect 31 link elements.
       3 => [
         [
@@ -185,7 +193,7 @@ class CssCollectionRendererUnitTest extends UnitTestCase {
       ],
       // 32 file CSS assets with the same properties, except for the 10th and
       // 20th files, they have different 'media' properties.
-      5 => [
+      4 => [
         [
           0 => $create_file_css_asset('public://css/1.css'),
           1 => $create_file_css_asset('public://css/2.css'),
@@ -264,10 +272,6 @@ class CssCollectionRendererUnitTest extends UnitTestCase {
    * @dataProvider providerTestRender
    */
   public function testRender(array $css_assets, array $render_elements) {
-    $this->state->expects($this->once())
-      ->method('get')
-      ->with('system.css_js_query_string')
-      ->will($this->returnValue(NULL));
     $this->assertSame($render_elements, $this->renderer->render($css_assets));
   }
 
@@ -275,10 +279,6 @@ class CssCollectionRendererUnitTest extends UnitTestCase {
    * Tests a CSS asset group with the invalid 'type' => 'internal'.
    */
   public function testRenderInvalidType() {
-    $this->state->expects($this->once())
-      ->method('get')
-      ->with('system.css_js_query_string')
-      ->will($this->returnValue(NULL));
     $this->expectException('Exception');
     $this->expectExceptionMessage('Invalid CSS asset type.');