diff --git a/includes/form.inc b/includes/form.inc
index c0e2ec7..9c7fae6 100644
--- a/includes/form.inc
+++ b/includes/form.inc
@@ -3892,7 +3892,7 @@ function theme_form_required_marker($variables) {
     'class' => 'form-required',
     'title' => $t('This field is required.'),
   );
-  return '<span' . drupal_attributes($attributes) . '>*</span>';
+  return '<abbr' . drupal_attributes($attributes) . '>*</abbr>';
 }
 
 /**