diff --git a/core/modules/layout_builder/tests/src/Functional/LayoutRecursionTest.php b/core/modules/layout_builder/tests/src/Functional/LayoutRecursionTest.php
index 412ce85dba..ce4c803d37 100644
--- a/core/modules/layout_builder/tests/src/Functional/LayoutRecursionTest.php
+++ b/core/modules/layout_builder/tests/src/Functional/LayoutRecursionTest.php
@@ -32,7 +32,7 @@ class LayoutRecursionTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp() {
+  protected function setUp(): void {
     parent::setUp();
 
     for ($i = 1; $i <= 9; $i++) {
diff --git a/core/modules/layout_builder/tests/src/Kernel/SectionComponentRecursionTest.php b/core/modules/layout_builder/tests/src/Kernel/SectionComponentRecursionTest.php
index 418726f785..a030d9131b 100644
--- a/core/modules/layout_builder/tests/src/Kernel/SectionComponentRecursionTest.php
+++ b/core/modules/layout_builder/tests/src/Kernel/SectionComponentRecursionTest.php
@@ -28,7 +28,7 @@ class SectionComponentRecursionTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  protected function setUp() {
+  protected function setUp(): void {
     parent::setUp();
     $this->installEntitySchema('entity_test');
   }