diff --git a/core/modules/search/lib/Drupal/search/SearchPageListController.php b/core/modules/search/lib/Drupal/search/SearchPageListController.php
index e835c01..6d1fb08 100644
--- a/core/modules/search/lib/Drupal/search/SearchPageListController.php
+++ b/core/modules/search/lib/Drupal/search/SearchPageListController.php
@@ -281,11 +281,11 @@ public function submitForm(array &$form, array &$form_state) {
     if (($search_settings->get('index.minimum_word_size') != $form_state['values']['minimum_word_size']) || ($search_settings->get('index.overlap_cjk') != $form_state['values']['overlap_cjk'])) {
       $search_settings->set('index.minimum_word_size', $form_state['values']['minimum_word_size']);
       $search_settings->set('index.overlap_cjk', $form_state['values']['overlap_cjk']);
+      $search_settings->save();
       drupal_set_message($this->t('The index will be rebuilt.'));
       search_reindex();
     }
 
-
     drupal_set_message($this->t('The configuration options have been saved.'));
   }
 
diff --git a/core/modules/search/lib/Drupal/search/Tests/SearchConfigSettingsFormTest.php b/core/modules/search/lib/Drupal/search/Tests/SearchConfigSettingsFormTest.php
index 8fe78fb..67333a9 100644
--- a/core/modules/search/lib/Drupal/search/Tests/SearchConfigSettingsFormTest.php
+++ b/core/modules/search/lib/Drupal/search/Tests/SearchConfigSettingsFormTest.php
@@ -85,12 +85,29 @@ function testSearchSettingsPage() {
     $this->drupalPostForm('admin/config/search/settings', array(), t('Save configuration'));
     $this->assertText(t('The configuration options have been saved.'), 'Form saves with the default values.');
 
+    // Ensure that the default settings were picked up from the default config
+    $search_settings = \Drupal::config('search.settings');
+    $this->assertEqual($search_settings->get('index.minimum_word_size'), 3, 'Minimum word length was picked up from the default config');
+    $this->assertTrue($search_settings->get('index.overlap_cjk'), 'Simple CJK handling was picked up from the default config');
+
+    // Test that the form saves changes to minimum word length and simple CJK handling.
+    $edit = array(
+      'minimum_word_size' => 5,
+      'overlap_cjk' => FALSE,
+    );
+    $this->drupalPostForm('admin/config/search/settings', $edit, t('Save configuration'));
+    $this->assertText(t('The index will be rebuilt.'), 'Index is rebuilt when minimum word length and simple CJK handling options are changed.');
+    $search_settings = \Drupal::config('search.settings');
+    $this->assertEqual($search_settings->get('index.minimum_word_size'), 5, 'Change to minimum word length option was saved.');
+    $this->assertFalse($search_settings->get('index.overlap_cjk'), 'Change to simple CJK handling option was saved.');
+
     // Test that the form does not save with an invalid word length.
     $edit = array(
       'minimum_word_size' => $this->randomName(3),
     );
     $this->drupalPostForm('admin/config/search/settings', $edit, t('Save configuration'));
     $this->assertNoText(t('The configuration options have been saved.'), 'Form does not save with an invalid word length.');
+    $this->assertNoText(t('The index will be rebuilt.'), 'Index is not rebuilt when failing to change minimum word length.');
   }
 
   /**