diff --git a/src/Form/FlagForListForm.php b/src/Form/FlagForListForm.php
index 5ab0f3b..efa615f 100644
--- a/src/Form/FlagForListForm.php
+++ b/src/Form/FlagForListForm.php
@@ -74,7 +74,8 @@ class FlagForListForm extends EntityForm {
       // Configuration entities need an ID manually set.
       $machine_name = \Drupal::transliteration()
           ->transliterate($label, LanguageInterface::LANGCODE_DEFAULT, '_');
-      $flag_for_list->set('id', mb_strtolower($machine_name));
+      $machineName = $machine_name ? str_replace([' ', '_', '[', ']'], ['-', '-', '-', ''], mb_strtolower($imachine_named)) : '';
+      $flag_for_list->set('id', $machineName);
       $flag_for_list->set('weight', '0');
 
       $this->messenger()->addMessage(t('The %label flag list has been created.', ['%label' => $flag_for_list->label()]));