diff --git a/core/modules/layout_builder/src/Element/LayoutBuilder.php b/core/modules/layout_builder/src/Element/LayoutBuilder.php
index 05f4d5a06e..dd65f05aa1 100644
--- a/core/modules/layout_builder/src/Element/LayoutBuilder.php
+++ b/core/modules/layout_builder/src/Element/LayoutBuilder.php
@@ -5,6 +5,7 @@
 use Drupal\Component\Plugin\DerivativeInspectionInterface;
 use Drupal\Core\Ajax\AjaxHelperTrait;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Messenger\MessengerInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\Core\Plugin\PluginFormInterface;
 use Drupal\Core\Render\Element;
@@ -59,17 +60,14 @@ class LayoutBuilder extends RenderElement implements ContainerFactoryPluginInter
    *   The plugin implementation definition.
    * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
    *   The event dispatcher service.
-   * @param \Drupal\Core\Messenger\MessengerInterface|null $messenger
-   *   The messenger service. This is no longer used and will be removed in
-   *   drupal:10.0.0.
-   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   * @param \Drupal\Core\Messenger\MessengerInterface|\Drupal\Core\Entity\EntityTypeManagerInterface|null $entity_type_manager
    *   (optional) The entity type manager.
    *
    * @todo The current constructor signature is deprecated:
    *   - The $entity_type_manager parameter is optional but should become
    *   required. Deprecate in https://www.drupal.org/node/3058490.
    */
-  public function __construct(array $configuration, $plugin_id, $plugin_definition, $event_dispatcher, $messenger = NULL, EntityTypeManagerInterface $entity_type_manager = NULL) {
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, $event_dispatcher, $entity_type_manager = NULL) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
 
     if (!($event_dispatcher instanceof EventDispatcherInterface)) {
@@ -78,11 +76,11 @@ public function __construct(array $configuration, $plugin_id, $plugin_definition
     }
     $this->eventDispatcher = $event_dispatcher;
 
-    if ($messenger) {
+    if ($entity_type_manager instanceof MessengerInterface) {
       @trigger_error('Calling LayoutBuilder::__construct() with the $messenger argument is deprecated in drupal:9.1.0 and will be removed in drupal:10.0.0. See https://www.drupal.org/node/3152690', E_USER_DEPRECATED);
     }
 
-    if ($entity_type_manager === NULL) {
+    if ($entity_type_manager === NULL || !$entity_type_manager instanceof EntityTypeManagerInterface) {
       @trigger_error('The entity_type.manager service must be passed to \Drupal\layout_builder\Element\LayoutBuilder::__construct(). It was added in Drupal 8.8.0 and will be required before Drupal 9.0.0.', E_USER_DEPRECATED);
       $entity_type_manager = \Drupal::service('entity_type.manager');
     }