diff --git a/core/modules/layout_builder/tests/src/Unit/SectionComponentTest.php b/core/modules/layout_builder/tests/src/Unit/SectionComponentTest.php
index ca2138ec9ee7..e50fe65e3586 100644
--- a/core/modules/layout_builder/tests/src/Unit/SectionComponentTest.php
+++ b/core/modules/layout_builder/tests/src/Unit/SectionComponentTest.php
@@ -12,7 +12,7 @@ use Drupal\layout_builder\LayoutBuilderEvents;
 use Drupal\layout_builder\SectionComponent;
 use Drupal\Tests\UnitTestCase;
 use Prophecy\Argument;
-use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
 
 /**
  * @coversDefaultClass \Drupal\layout_builder\SectionComponent
@@ -39,7 +39,7 @@ class SectionComponentTest extends UnitTestCase {
         /** @var \Drupal\layout_builder\Event\SectionComponentBuildRenderArrayEvent $event */
         $event = $args[0];
         $event->setBuild(['#markup' => $event->getPlugin()->getPluginId()]);
-        return;
+        return $event;
       });
 
     $layout_plugin = $this->prophesize(LayoutInterface::class);
diff --git a/core/tests/Drupal/Tests/Core/Session/AccountProxyTest.php b/core/tests/Drupal/Tests/Core/Session/AccountProxyTest.php
index ae233a5cb918..33f9323bbafc 100644
--- a/core/tests/Drupal/Tests/Core/Session/AccountProxyTest.php
+++ b/core/tests/Drupal/Tests/Core/Session/AccountProxyTest.php
@@ -5,6 +5,8 @@ namespace Drupal\Tests\Core\Session;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\Session\AccountProxy;
 use Drupal\Tests\UnitTestCase;
+use Prophecy\Argument;
+use Symfony\Contracts\EventDispatcher\Event;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
 /**
@@ -19,6 +21,7 @@ class AccountProxyTest extends UnitTestCase {
    */
   public function testId() {
     $dispatcher = $this->prophesize(EventDispatcherInterface::class);
+    $dispatcher->dispatch(Argument::any(), Argument::any())->willReturn(new Event());
     $account_proxy = new AccountProxy($dispatcher->reveal());
     $this->assertSame(0, $account_proxy->id());
     $account_proxy->setInitialAccountId(1);
@@ -39,6 +42,7 @@ class AccountProxyTest extends UnitTestCase {
   public function testSetInitialAccountIdException() {
     $this->expectException(\LogicException::class);
     $dispatcher = $this->prophesize(EventDispatcherInterface::class);
+    $dispatcher->dispatch(Argument::any(), Argument::any())->willReturn(new Event());
     $account_proxy = new AccountProxy($dispatcher->reveal());
     $current_user = $this->prophesize(AccountInterface::class);
     $account_proxy->setAccount($current_user->reveal());