diff a/sites/all/modules/conditional_fields/conditional_fields.module b/sites/all/modules/conditional_fields/conditional_fields.module
--- a/sites/all/modules/conditional_fields/conditional_fields.module
+++ b/sites/all/modules/conditional_fields/conditional_fields.module
@@ -646,6 +646,7 @@ function conditional_fields_form_after_build($form, &$form_state) {
     return $form;
   }
 
+  $form['#attached']['js'][] = 'misc/states.js';
   $form['#attached']['js'][] = drupal_get_path('module', 'conditional_fields') . '/js/conditional_fields.js';
 
   // Add effect settings to the form.