diff --git a/multiselect.module b/multiselect.module
index 8966df0..3dd8ea7 100644
--- a/multiselect.module
+++ b/multiselect.module
@@ -202,6 +202,8 @@ function _multiselect_build_widget_code($options, $items, $element, $required =
   }
 
   // Set up useful variables.
+  $element['#field_name'] = drupal_html_id('edit-' . implode('-', $element['#field_parents']));
+
   $selfield = $element['#field_name'] . "_sel";
   $unselfield = $element['#field_name'] . "_unsel";