diff --git a/core/modules/content_moderation/src/Plugin/Field/ModerationStateFieldItemList.php b/core/modules/content_moderation/src/Plugin/Field/ModerationStateFieldItemList.php
index 8ac1736..86354b4 100644
--- a/core/modules/content_moderation/src/Plugin/Field/ModerationStateFieldItemList.php
+++ b/core/modules/content_moderation/src/Plugin/Field/ModerationStateFieldItemList.php
@@ -5,6 +5,7 @@
 use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityPublishedInterface;
 use Drupal\Core\Field\FieldItemList;
+use Drupal\Core\TypedData\ComputedItemListTrait;
 
 /**
  * A computed field that provides a content entity's moderation state.
@@ -14,6 +15,20 @@
  */
 class ModerationStateFieldItemList extends FieldItemList {
 
+  use ComputedItemListTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function computeValue() {
+    $moderation_state = $this->getModerationStateId();
+    // Do not store NULL values in the static cache.
+    if ($moderation_state) {
+      // An entity can only have a single moderation state.
+      $this->list[0] = $this->createItem(0, $moderation_state);
+    }
+  }
+
   /**
    * Gets the moderation state ID linked to a content entity revision.
    *
@@ -86,49 +101,6 @@ protected function loadContentModerationStateRevision(ContentEntityInterface $en
   /**
    * {@inheritdoc}
    */
-  public function get($index) {
-    if ($index !== 0) {
-      throw new \InvalidArgumentException('An entity can not have multiple moderation states at the same time.');
-    }
-    $this->computeModerationFieldItemList();
-    return isset($this->list[$index]) ? $this->list[$index] : NULL;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getIterator() {
-    $this->computeModerationFieldItemList();
-    return parent::getIterator();
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getValue($include_computed = FALSE) {
-    $this->computeModerationFieldItemList();
-    return parent::getValue($include_computed);
-  }
-
-  /**
-   * Recalculate the moderation field item list.
-   */
-  protected function computeModerationFieldItemList() {
-    // Compute the value of the moderation state.
-    $index = 0;
-    if (!isset($this->list[$index]) || $this->list[$index]->isEmpty()) {
-
-      $moderation_state = $this->getModerationStateId();
-      // Do not store NULL values in the static cache.
-      if ($moderation_state) {
-        $this->list[$index] = $this->createItem($index, $moderation_state);
-      }
-    }
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function onChange($delta) {
     $this->updateModeratedEntity($this->list[$delta]->value);