diff --git a/unique_field_ajax.module b/unique_field_ajax.module
index 114bb66..c0213bc 100644
--- a/unique_field_ajax.module
+++ b/unique_field_ajax.module
@@ -40,6 +40,7 @@ function unique_field_ajax_form_field_config_edit_form_alter(&$form, FormStateIn
   $field = $form_state->getFormObject()->getEntity();
   $unique_field_ajax_types = [
     'string',
+    'string_long',
     'list_string',
     'text',
     'email',