diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/EntityReferenceAutocompleteWidget.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/EntityReferenceAutocompleteWidget.php
index 493d6a4..626d13c 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/EntityReferenceAutocompleteWidget.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/EntityReferenceAutocompleteWidget.php
@@ -145,7 +145,16 @@ public function massageFormValues(array $values, array $form, FormStateInterface
    */
   protected function getAutocreateBundle() {
     $bundle = NULL;
-    if ($this->getSelectionHandlerSetting('auto_create') && $target_bundles = $this->getSelectionHandlerSetting('target_bundles')) {
+    if ($this->getSelectionHandlerSetting('auto_create')) {
+      $target_bundles = $this->getSelectionHandlerSetting('target_bundles');
+
+      // A NULL value for the 'target_bundles' selection handler setting means
+      // that all bundles are referenceable.
+      // @see \Drupal\Core\Entity\Plugin\EntityReferenceSelection\DefaultSelection::defaultConfiguration()
+      if ($target_bundles === NULL) {
+        $target_bundles = array_keys(\Drupal::service('entity_type.bundle.info')->getBundleInfo($this->getSelectionHandlerSetting('target_type')));
+      }
+
       // If there's only one target bundle, use it.
       if (count($target_bundles) == 1) {
         $bundle = reset($target_bundles);