diff --git a/core/lib/Drupal/Core/TypedData/ComputedItemListTrait.php b/core/lib/Drupal/Core/TypedData/ComputedItemListTrait.php
index f6660c4..182a946 100644
--- a/core/lib/Drupal/Core/TypedData/ComputedItemListTrait.php
+++ b/core/lib/Drupal/Core/TypedData/ComputedItemListTrait.php
@@ -11,6 +11,8 @@
  * @see \Drupal\Core\Field\FieldItemList
  *
  * @ingroup typed_data
+ *
+ * @internal
  */
 trait ComputedItemListTrait {
 
diff --git a/core/lib/Drupal/Core/TypedData/Plugin/DataType/ItemList.php b/core/lib/Drupal/Core/TypedData/Plugin/DataType/ItemList.php
index f2861d6..4f756da 100644
--- a/core/lib/Drupal/Core/TypedData/Plugin/DataType/ItemList.php
+++ b/core/lib/Drupal/Core/TypedData/Plugin/DataType/ItemList.php
@@ -98,10 +98,7 @@ public function get($index) {
       throw new \InvalidArgumentException('Unable to get a value with a non-numeric delta in a list.');
     }
     // Automatically create the first item for computed fields.
-    // @deprecated in Drupal 8.4.x, will be removed before Drupal 9.0.0.
-    // Use \Drupal\Core\TypedData\ComputedItemListTrait instead.
     if ($index == 0 && !isset($this->list[0]) && $this->definition->isComputed()) {
-      @trigger_error('Automatically creating the first item for computed fields is deprecated in Drupal 8.4.x and will be removed before Drupal 9.0.0. Use \Drupal\Core\TypedData\ComputedItemListTrait instead.', E_USER_DEPRECATED);
       $this->list[0] = $this->createItem(0);
     }
     return isset($this->list[$index]) ? $this->list[$index] : NULL;