diff --git a/core/includes/form.inc b/core/includes/form.inc
index 3c88b1e..77a9f5e 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -2786,7 +2786,7 @@ function form_get_options($element, $key) {
  *   An associative array containing:
  *   - element: An associative array containing the properties of the element.
  *     Properties used: #attributes, #children, #collapsed, #collapsible,
- *     #description, #id, #title, #value.
+ *     #description, #id, #title, #title_display, #value.
  *
  * @ingroup themeable
  */
@@ -2795,21 +2795,29 @@ function theme_fieldset($variables) {
   element_set_attributes($element, array('id'));
   _form_set_attributes($element, array('form-wrapper'));
 
-  if (!empty($element['#description'])) {
-    $description_id = $element['#attributes']['id'] . '--description';
-    $element['#attributes']['aria-describedby'] = $description_id;
+  // Add the aria-describedby attribute to associate the fieldset with its
+  // description.
+  $description_attributes = array(
+    'class' => array('fieldset-description'),
+  );
+  if (!empty($element['#description']) && isset($element['#attributes']['id'])) {
+    $description_attributes['id'] = $element['#attributes']['id'] . '--description';
+    $element['#attributes']['aria-describedby'] = $description_attributes['id'];
   }
 
   $output = '<fieldset' . new Attribute($element['#attributes']) . '>';
-  if (!empty($element['#title'])) {
+  $element += array('#title_display' => 'before');
+  if (!empty($element['#title']) && !in_array($element['#title_display'], array('none', 'attribute'), TRUE)) {
+    $attributes = new Attribute(array('class' => array('fieldset-legend')));
+    if ($element['#title_display'] === 'invisible') {
+      $attributes['class'][] = 'element-invisible';
+    }
     // Always wrap fieldset legends in a SPAN for CSS positioning.
-    $output .= '<legend><span class="fieldset-legend">' . $element['#title'] . '</span></legend>';
+    $output .= '<legend><span' . $attributes . '>' . $element['#title'] . '</span></legend>';
   }
   $output .= '<div class="fieldset-wrapper">';
   if (!empty($element['#description'])) {
-    $attributes = array('class' => 'fieldset-description', 'id' => $description_id);
-    $output .= '<div' . new Attribute($attributes) . '>' . $element['#description'] . '</div>';
-
+    $output .= '<div' . new Attribute($description_attributes) . '>' . $element['#description'] . '</div>';
   }
   $output .= $element['#children'];
   if (isset($element['#value'])) {
@@ -4531,14 +4539,29 @@ function theme_form_element($variables) {
   if (!empty($element['#attributes']['disabled'])) {
     $attributes['class'][] = 'form-disabled';
   }
+  $prefix = isset($element['#field_prefix']) ? '<span class="field-prefix">' . $element['#field_prefix'] . '</span> ' : '';
+  $suffix = isset($element['#field_suffix']) ? ' <span class="field-suffix">' . $element['#field_suffix'] . '</span>' : '';
+
+  // Composite elements consist of more than one HTML form control. These must
+  // be grouped by a fieldset.
+  if (isset($element['#composite']) && $element['#composite'] === TRUE) {
+    $fieldset_variables = array('element' => array());
+    $fieldset_variables['element']['#children'] = $prefix . $element['#children'] . $suffix;
+    foreach (array('#attributes', '#description', '#id', '#title', '#title_display') as $property) {
+      if (!empty($element[$property])) {
+        $fieldset_variables['element'][$property] = $element[$property];
+      }
+    }
+    unset($fieldset_variables['element']['#attributes']['disabled']);
+    $fieldset_variables['element']['#title'] .= !empty($element['#required']) ? ' ' . theme('form_required_marker', array('element' => $element)) : '';
+    return theme('fieldset', $fieldset_variables);
+  }
   $output = '<div' . new Attribute($attributes) . '>' . "\n";
 
   // If #title is not set, we don't display any label or required marker.
   if (!isset($element['#title'])) {
     $element['#title_display'] = 'none';
   }
-  $prefix = isset($element['#field_prefix']) ? '<span class="field-prefix">' . $element['#field_prefix'] . '</span> ' : '';
-  $suffix = isset($element['#field_suffix']) ? ' <span class="field-suffix">' . $element['#field_suffix'] . '</span>' : '';
 
   switch ($element['#title_display']) {
     case 'before':
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/FormTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/FormTest.php
index 9efe0c3..e0ff73c 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/FormTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/FormTest.php
@@ -95,7 +95,7 @@ function testRequiredFields() {
     $elements['file']['empty_values'] = $empty_strings;
 
     // Regular expression to find the expected marker on required elements.
-    $required_marker_preg = '@<label.*<abbr class="form-required" title="This field is required\.">\*</abbr></label>@';
+    $required_marker_preg = '@<(label|legend).*<abbr class="form-required" title="This field is required\.">\*</abbr>.*</\1>@';
 
     // Go through all the elements and all the empty values for them.
     foreach ($elements as $type => $data) {
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 1492cf0..5063ecd 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -430,6 +430,7 @@ function system_element_info() {
     '#theme_wrappers' => array('form_element'),
   );
   $types['radios'] = array(
+    '#composite' => TRUE,
     '#input' => TRUE,
     '#process' => array('form_process_radios'),
     '#theme_wrappers' => array('radios'),
@@ -444,6 +445,7 @@ function system_element_info() {
     '#title_display' => 'after',
   );
   $types['checkboxes'] = array(
+    '#composite' => TRUE,
     '#input' => TRUE,
     '#process' => array('form_process_checkboxes'),
     '#theme_wrappers' => array('checkboxes'),
@@ -475,6 +477,7 @@ function system_element_info() {
     '#process' => array('form_process_weight', 'ajax_process_form'),
   );
   $types['date'] = array(
+    '#composite' => TRUE,
     '#input' => TRUE,
     '#element_validate' => array('date_validate'),
     '#process' => array('form_process_date'),