diff -u b/core/lib/Drupal/Core/Entity/Element/EntityAutocomplete.php b/core/lib/Drupal/Core/Entity/Element/EntityAutocomplete.php
--- b/core/lib/Drupal/Core/Entity/Element/EntityAutocomplete.php
+++ b/core/lib/Drupal/Core/Entity/Element/EntityAutocomplete.php
@@ -4,5 +4,6 @@
 use Drupal\Component\Utility\Crypt;
 use Drupal\Component\Utility\Tags;
+use Drupal\Core\Entity\EntityForm;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityReferenceSelection\SelectionInterface;
 use Drupal\Core\Entity\EntityReferenceSelection\SelectionWithAutocreateInterface;
@@ -130,7 +131,7 @@
 
     // Put entity into settings.
     $form_object = $form_state->getFormObject();
-    if (isset($form_object)) {
+    if (isset($form_object) && $form_object instanceof EntityForm) {
       $entity = $form_object->getEntity();
       if (isset($entity)) {
         $storage = $form_state->getStorage();