diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
index 02b7997..8ccc512 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
@@ -41,7 +41,7 @@ class EntityReferenceItem extends FieldItemBase {
    *
    * @var int
    */
-  protected const NEW_ENTITY_MARKER = -1;
+  const NEW_ENTITY_MARKER = -1;
 
   /**
    * {@inheritdoc}