diff --git a/core/modules/language/tests/src/Unit/Plugin/LanguageNegotiation/LanguageNegotiationBrowserTest.php b/core/modules/language/tests/src/Unit/Plugin/LanguageNegotiation/LanguageNegotiationBrowserTest.php
index 686db85af4..00700fb829 100644
--- a/core/modules/language/tests/src/Unit/Plugin/LanguageNegotiation/LanguageNegotiationBrowserTest.php
+++ b/core/modules/language/tests/src/Unit/Plugin/LanguageNegotiation/LanguageNegotiationBrowserTest.php
@@ -39,7 +39,7 @@ class LanguageNegotiationBrowserTest extends UnitTestCase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp() {
+  protected function setUp(): void {
 
     // Set up some languages to be used by the language-based path processor.
     $language_de = $this->createMock(LanguageInterface::class);
@@ -56,7 +56,6 @@ protected function setUp() {
     ];
     $this->languages = $languages;
 
-    // Create a language manager stub.
     $language_manager = $this->getMockBuilder(ConfigurableLanguageManagerInterface::class)
       ->getMock();
     $language_manager->expects($this->any())
@@ -64,7 +63,6 @@ protected function setUp() {
       ->will($this->returnValue($languages));
     $this->languageManager = $language_manager;
 
-    // Create a user stub.
     $this->user = $this->getMockBuilder(AccountInterface::class)
       ->getMock();