diff --git a/core/includes/form.inc b/core/includes/form.inc
index 5f580fb..6b71de3 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -2786,12 +2786,12 @@ function theme_fieldset($variables) {
   _form_set_class($element, array('form-wrapper'));
 
   $output = '<fieldset' . new Attribute($element['#attributes']) . '>';
-  if (!empty($element['#title'])) {
+  if (isset($element['#title']) && (string) $element['#title'] !== '') {
     // Always wrap fieldset legends in a SPAN for CSS positioning.
     $output .= '<legend><span class="fieldset-legend">' . $element['#title'] . '</span></legend>';
   }
   $output .= '<div class="fieldset-wrapper">';
-  if (!empty($element['#description'])) {
+  if (isset($element['#description']) && (string) $element['#description'] !== '') {
     $output .= '<div class="fieldset-description">' . $element['#description'] . '</div>';
   }
   $output .= $element['#children'];