diff --git a/core/modules/search/search.admin.inc b/core/modules/search/search.admin.inc
index 5355c6a..4b47af9 100644
--- a/core/modules/search/search.admin.inc
+++ b/core/modules/search/search.admin.inc
@@ -60,75 +60,80 @@ function search_admin_settings($form) {
     }
   }
 
+  // Indexing configuration.
+  $form['indexing'] = array(
+    '#type' => 'fieldset',
+    '#title' => t('Indexing'),
+    '#description' => t("Changing these settings will cause the site index to be systematically updated to reflect the new settings. Searching will continue to work, but new content will not be indexed until all existing content has been re-indexed."),
+  );
   $count = format_plural($remaining, 'There is 1 item left to index.', 'There are @count items left to index.');
   $percentage = ((int)min(100, 100 * ($total - $remaining) / max(1, $total))) . '%';
   $status = '<p><strong>' . t('%percentage of the site has been indexed.', array('%percentage' => $percentage)) . ' ' . $count . '</strong></p>';
-  $form['status'] = array('#type' => 'fieldset', '#title' => t('Indexing status'));
-  $form['status']['status'] = array('#markup' => $status);
-  $form['status']['wipe'] = array('#type' => 'submit', '#value' => t('Re-index site'), '#submit' => array('search_admin_reindex_submit'));
-
-  $items = drupal_map_assoc(array(10, 20, 50, 100, 200, 500));
-
-  // Indexing throttle:
-  $form['indexing_throttle'] = array(
-    '#type' => 'fieldset',
-    '#title' => t('Indexing throttle')
+  $form['indexing']['status'] = array(
+    '#markup' => $status,
   );
-  $form['indexing_throttle']['search_cron_limit'] = array(
+  $form['indexing']['wipe'] = array(
+    '#type' => 'submit',
+    '#value' => t('Re-index site'),
+    '#submit' => array('search_admin_reindex_submit'),
+  );
+  $items = drupal_map_assoc(array(10, 20, 50, 100, 200, 500));
+  $form['indexing']['search_cron_limit'] = array(
     '#type' => 'select',
     '#title' => t('Number of items to index per cron run'),
     '#default_value' => variable_get('search_cron_limit', 100),
     '#options' => $items,
-    '#description' => t('The maximum number of items indexed in each pass of a <a href="@cron">cron maintenance task</a>. If necessary, reduce the number of items to prevent timeouts and memory errors while indexing.', array('@cron' => url('admin/reports/status')))
+    '#description' => t('The maximum number of items to index during a <a href="@cron">cron maintenance task</a>. If necessary, reduce the number of items to prevent timeouts and memory errors while indexing.', array('@cron' => url('admin/reports/status')))
   );
-  // Indexing settings:
-  $form['indexing_settings'] = array(
-    '#type' => 'fieldset',
-    '#title' => t('Indexing settings')
-  );
-  $form['indexing_settings']['info'] = array(
-    '#markup' => t('<p><em>Changing the settings below will cause the site index to be rebuilt. The search index is not cleared but systematically updated to reflect the new settings. Searching will continue to work but new content won\'t be indexed until all existing content has been re-indexed.</em></p><p><em>The default settings should be appropriate for the majority of sites.</em></p>')
-  );
-  $form['indexing_settings']['minimum_word_size'] = array(
+  $form['indexing']['minimum_word_size'] = array(
     '#type' => 'number',
     '#title' => t('Minimum word length to index'),
     '#default_value' => variable_get('minimum_word_size', 3),
     '#size' => 5,
     '#maxlength' => 3,
     '#min' => 1,
-    '#description' => t('The number of characters a word has to be to be indexed. A lower setting means better search result ranking, but also a larger database. Each search query must contain at least one keyword that is this size (or longer).')
+    '#description' => t('A lower setting means better search result ranking, but also a larger database. Each search query must contain at least one keyword that has this many characters or more.')
   );
-  $form['indexing_settings']['overlap_cjk'] = array(
+  $form['indexing']['overlap_cjk'] = array(
     '#type' => 'checkbox',
-    '#title' => t('Simple CJK handling'),
+    '#title' => t('Simple Chinese/Japanese/Korean handling'),
     '#default_value' => variable_get('overlap_cjk', TRUE),
-    '#description' => t('Whether to apply a simple Chinese/Japanese/Korean tokenizer based on overlapping sequences. Turn this off if you want to use an external preprocessor for this instead. Does not affect other languages.')
+    '#description' => t('Apply a tokenizer based on overlapping sequences instead of using an external preprocessor. Does not affect other languages.')
   );
 
-  $form['active'] = array(
+  // Search modules configuration.
+  $form['modules'] = array(
     '#type' => 'fieldset',
-    '#title' => t('Active search modules')
+    '#title' => t('Search modules')
   );
   $module_options = _search_get_module_names();
-  $form['active']['search_active_modules'] = array(
+  $form['modules']['search_active_modules'] = array(
     '#type' => 'checkboxes',
     '#title' => t('Active modules'),
-    '#title_display' => 'invisible',
     '#default_value' => variable_get('search_active_modules', array('node', 'user')),
     '#options' => $module_options,
-    '#description' => t('Choose which search modules are active from the available modules.')
+    '#required' => TRUE,
   );
-  $form['active']['search_default_module'] = array(
-    '#title' => t('Default search module'),
-    '#type' => 'radios',
-    '#default_value' => variable_get('search_default_module', 'node'),
-    '#options' => $module_options,
-    '#description' => t('Choose which search module is the default.')
+  $form['modules']['search_default_module'] = array(
+    '#type' => 'item',
+    '#title' => t('Default module'),
+    '#required' => TRUE,
   );
+  foreach ($module_options as $name => $title) {
+    $form['modules']['search_default_module'][$name] = array(
+      '#type' => 'radio',
+      '#title' => $title,
+      '#parents' => array('search_default_module'),
+      '#default_value' => $name == variable_get('search_default_module', 'node'),
+      '#return_value' => $name,
+      '#name' => 'search_default_module',
+    );
+  }
+  
   $form['#validate'][] = 'search_admin_settings_validate';
   $form['#submit'][] = 'search_admin_settings_submit';
 
-  // Per module settings
+  // Per-module configuration.
   foreach (variable_get('search_active_modules', array('node', 'user')) as $module) {
     $added_form = module_invoke($module, 'search_admin');
     if (is_array($added_form)) {
@@ -144,12 +149,10 @@ function search_admin_settings($form) {
  */
 function search_admin_settings_validate($form, &$form_state) {
   // Check whether we selected a valid default.
-  if ($form_state['triggering_element']['#value'] != t('Reset to defaults')) {
-    $new_modules = array_filter($form_state['values']['search_active_modules']);
-    $default = $form_state['values']['search_default_module'];
-    if (!in_array($default, $new_modules, TRUE)) {
-      form_set_error('search_default_module', t('Your default search module is not selected as an active module.'));
-    }
+  $new_modules = array_filter($form_state['values']['search_active_modules']);
+  $default = $form_state['values']['search_default_module'];
+  if (!in_array($default, $new_modules, TRUE)) {
+    form_error($form['modules']['search_default_module'], t('The default search module must be selected as an active module.'));
   }
 }
 
@@ -164,13 +167,7 @@ function search_admin_settings_submit($form, &$form_state) {
     search_reindex();
   }
   $current_modules = variable_get('search_active_modules', array('node', 'user'));
-  // Check whether we are resetting the values.
-  if ($form_state['triggering_element']['#value'] == t('Reset to defaults')) {
-    $new_modules = array('node', 'user');
-  }
-  else {
-    $new_modules = array_filter($form_state['values']['search_active_modules']);
-  }
+  $new_modules = array_filter($form_state['values']['search_active_modules']);
   if (array_diff($current_modules, $new_modules)) {
     drupal_set_message(t('The active search modules have been changed.'));
     variable_set('menu_rebuild_needed', TRUE);
