diff --git a/tests/modules/inline_all_css_csp_test/src/EventSubscriber/CssPreRenderSubscriber.php b/tests/modules/inline_all_css_csp_test/src/EventSubscriber/CssPreRenderSubscriber.php
index b8d19b7..26b7a2f 100644
--- a/tests/modules/inline_all_css_csp_test/src/EventSubscriber/CssPreRenderSubscriber.php
+++ b/tests/modules/inline_all_css_csp_test/src/EventSubscriber/CssPreRenderSubscriber.php
@@ -13,7 +13,7 @@ class CssPreRenderSubscriber implements EventSubscriberInterface {
   /**
    * {@inheritdoc}
    */
-  public static function getSubscribedEvents() {
+  public static function getSubscribedEvents(): array {
     return [
       CssPreRenderEvent::EVENT_NAME => ['onCssPreRender', 0],
     ];
diff --git a/tests/src/Kernel/CssCollectionRendererTest.php b/tests/src/Kernel/CssCollectionRendererTest.php
index 7d681ce..222b71d 100644
--- a/tests/src/Kernel/CssCollectionRendererTest.php
+++ b/tests/src/Kernel/CssCollectionRendererTest.php
@@ -82,9 +82,7 @@ class CssCollectionRendererTest extends KernelTestBase {
    */
   protected function setUp(): void {
     parent::setUp();
-    $filesystem = $this->getMockBuilder(FileSystemInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $filesystem = $this->createMock(FileSystemInterface::class);
 
     $filesystem
       ->method('realpath')
@@ -94,33 +92,21 @@ class CssCollectionRendererTest extends KernelTestBase {
         ['public://test-3.css', __DIR__ . '/../../fixtures/test-3.css'],
       ]);
 
-    $this->eventDispatcher = $this->getMockBuilder(EventDispatcherInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $this->eventDispatcher = $this->createMock(EventDispatcherInterface::class);
 
-    $this->cssCollectionRenderer = $this->getMockBuilder(AssetCollectionRendererInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $this->cssCollectionRenderer = $this->createMock(AssetCollectionRendererInterface::class);
 
-    $this->themeManager = $this->getMockBuilder(ThemeManagerInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $this->themeManager = $this->createMock(ThemeManagerInterface::class);
 
-    $config_factory = $this->getMockBuilder(ConfigFactoryInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $config_factory = $this->createMock(ConfigFactoryInterface::class);
 
-    $this->config = $this->getMockBuilder(Config::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $this->config = $this->createMock(Config::class);
 
     $config_factory
       ->method('get')
       ->willReturn($this->config);
 
-    $stream = $this->getMockBuilder(StreamInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $stream = $this->createMock(StreamInterface::class);
 
     $stream
       ->method('getContents')
@@ -132,40 +118,28 @@ div {
 CSS
     );
 
-    $response = $this->getMockBuilder(ResponseInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $response = $this->createMock(ResponseInterface::class);
 
     $response
       ->method('getBody')
       ->willReturn($stream);
 
-    $http_client = $this->getMockBuilder(ClientInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $http_client = $this->createMock(ClientInterface::class);
 
     $http_client
       ->method('request')
       ->willReturn($response);
 
-    $logger = $this->getMockBuilder(LoggerChannelInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $logger = $this->createMock(LoggerChannelInterface::class);
 
-    $logger_factory = $this->getMockBuilder(LoggerChannelFactoryInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $logger_factory = $this->createMock(LoggerChannelFactoryInterface::class);
 
     $logger_factory
       ->method('get')
       ->willReturn($logger);
 
-    $request_stack = $this->getMockBuilder(RequestStack::class)
-      ->disableOriginalConstructor()
-      ->getMock();
-    $this->request = $this->getMockBuilder(Request::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $request_stack = $this->createMock(RequestStack::class);
+    $this->request = $this->createMock(Request::class);
     $request_stack
       ->method('getCurrentRequest')
       ->willReturn($this->request);
@@ -214,9 +188,7 @@ CSS;
    *   The theme to set.
    */
   protected function setActiveTheme($theme) {
-    $active_theme = $this->getMockBuilder(ActiveTheme::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $active_theme = $this->createMock(ActiveTheme::class);
 
     $active_theme
       ->method('getName')
diff --git a/tests/src/Unit/MinifySubscriberTest.php b/tests/src/Unit/MinifySubscriberTest.php
index 0b39e57..c0318fc 100644
--- a/tests/src/Unit/MinifySubscriberTest.php
+++ b/tests/src/Unit/MinifySubscriberTest.php
@@ -59,9 +59,7 @@ CSS;
   protected function setUp(): void {
     parent::setUp();
 
-    $config = $this->getMockBuilder(ImmutableConfig::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $config = $this->createMock(ImmutableConfig::class);
 
     $config
       ->method('get')
@@ -69,9 +67,7 @@ CSS;
         return $this->minificationEnabled;
       });
 
-    $config_factory = $this->getMockBuilder(ConfigFactoryInterface::class)
-      ->disableOriginalConstructor()
-      ->getMock();
+    $config_factory = $this->createMock(ConfigFactoryInterface::class);
 
     $config_factory
       ->method('get')