diff --git a/core/modules/book/book.admin.inc b/core/modules/book/book.admin.inc
index 7d007c4..8fefc78 100644
--- a/core/modules/book/book.admin.inc
+++ b/core/modules/book/book.admin.inc
@@ -32,12 +32,13 @@ function book_admin_overview() {
  * @see book_admin_settings_validate()
  * @ingroup forms
  */
-function book_admin_settings() {
+function book_admin_settings($form, $form_state) {
   $types = node_type_get_names();
+  $config = config('book.settings');
   $form['book_allowed_types'] = array(
     '#type' => 'checkboxes',
     '#title' => t('Content types allowed in book outlines'),
-    '#default_value' => variable_get('book_allowed_types', array('book')),
+    '#default_value' => $config->get('allowed_types'),
     '#options' => $types,
     '#description' => t('Users with the %outline-perm permission can add all content types.', array('%outline-perm' => t('Administer book outlines'))),
     '#required' => TRUE,
@@ -45,14 +46,14 @@ function book_admin_settings() {
   $form['book_child_type'] = array(
     '#type' => 'radios',
     '#title' => t('Content type for child pages'),
-    '#default_value' => variable_get('book_child_type', 'book'),
+    '#default_value' => $config->get('child_type'),
     '#options' => $types,
     '#required' => TRUE,
   );
   $form['array_filter'] = array('#type' => 'value', '#value' => TRUE);
   $form['#validate'][] = 'book_admin_settings_validate';
 
-  return system_settings_form($form);
+  return system_config_form($form, $form_state);
 }
 
 /**
@@ -66,6 +67,18 @@ function book_admin_settings_validate($form, &$form_state) {
 }
 
 /**
+ * Form submission handler for book_admin_settings().
+ *
+ * @see book_admin_settings()
+ */
+function book_admin_settings_submit($form, &$form_state) {
+  config('book.settings')
+    ->set('allowed_types', $form_state['values']['book_allowed_types'])
+    ->set('child_type', $form_state['values']['book_child_type'])
+    ->save();
+ }
+
+/**
  * Form constructor for administering a single book's hierarchy.
  *
  * @param Drupal\node\Node $node
diff --git a/core/modules/book/book.install b/core/modules/book/book.install
index 899ee81..bdc4a28 100644
--- a/core/modules/book/book.install
+++ b/core/modules/book/book.install
@@ -17,10 +17,6 @@ function book_install() {
  * Implements hook_uninstall().
  */
 function book_uninstall() {
-  variable_del('book_allowed_types');
-  variable_del('book_child_type');
-  variable_del('book_block_mode');
-
   // Delete menu links.
   db_delete('menu_links')
     ->condition('module', 'book')
@@ -48,9 +44,6 @@ function _book_install_type_create() {
   node_add_body_field($book_node_type);
   // Default to not promoted.
   variable_set('node_options_book', array('status'));
-  // Use this default type for adding content to books.
-  variable_set('book_allowed_types', array('book'));
-  variable_set('book_child_type', 'book');
 }
 
 /**
@@ -93,3 +86,16 @@ function book_schema() {
 
   return $schema;
 }
+
+/**
+ * Moves book settings from variables to config.
+ *
+ * @ingroup config_upgrade
+ */
+function book_update_8000() {
+  update_variables_to_config('book.settings', array(
+    'book_allowed_types' => 'allowed_types',
+    'book_child_type' => 'child_type',
+    'book_block_mode' => 'block_mode',
+  ));
+}
diff --git a/core/modules/book/book.module b/core/modules/book/book.module
index 40802a1..559752e 100644
--- a/core/modules/book/book.module
+++ b/core/modules/book/book.module
@@ -98,7 +98,7 @@ function book_node_view_link(Node $node, $view_mode) {
 
   if (isset($node->book['depth'])) {
     if ($view_mode == 'full' && node_is_page($node)) {
-      $child_type = variable_get('book_child_type', 'book');
+      $child_type = config('book.settings')->get('child_type');
       if ((user_access('add content to books') || user_access('administer book outlines')) && node_access('create', $child_type) && $node->status == 1 && $node->book['depth'] < MENU_MAX_DEPTH) {
         $links['book_add_child'] = array(
           'title' => t('Add child page'),
@@ -284,7 +284,7 @@ function book_block_view($delta = '') {
     $current_bid = empty($node->book['bid']) ? 0 : $node->book['bid'];
   }
 
-  if (variable_get('book_block_mode', 'all pages') == 'all pages') {
+  if (config('book.settings')->get('block_mode') == 'all pages') {
     $block['subject'] = t('Book navigation');
     $book_menus = array();
     $pseudo_tree = array(0 => array('below' => FALSE));
@@ -342,7 +342,7 @@ function book_block_configure($delta = '') {
     '#type' => 'radios',
     '#title' => t('Book navigation block display'),
     '#options' => $options,
-    '#default_value' => variable_get('book_block_mode', 'all pages'),
+    '#default_value' => config('book.settings')->get('block_mode'),
     '#description' => t("If <em>Show block on all pages</em> is selected, the block will contain the automatically generated menus for all of the site's books. If <em>Show block only on book pages</em> is selected, the block will contain only the one menu corresponding to the current page's book. In this case, if the current page is not in a book, no block will be displayed. The <em>Page specific visibility settings</em> or other visibility settings can be used in addition to selectively display this block."),
     );
 
@@ -354,7 +354,7 @@ function book_block_configure($delta = '') {
  */
 function book_block_save($delta = '', $edit = array()) {
   $block = array();
-  variable_set('book_block_mode', $edit['book_block_mode']);
+  config('book.settings')->set('block_mode', $edit['book_block_mode'])->save();
 }
 
 /**
@@ -1327,7 +1327,7 @@ function template_preprocess_book_node_export_html(&$variables) {
  * Determines if a given node type is in the list of types allowed for books.
  */
 function book_type_is_allowed($type) {
-  return in_array($type, variable_get('book_allowed_types', array('book')));
+  return in_array($type, config('book.settings')->get('allowed_types'));
 }
 
 /**
@@ -1338,20 +1338,22 @@ function book_type_is_allowed($type) {
  */
 function book_node_type_update($type) {
   if (!empty($type->old_type) && $type->old_type != $type->type) {
+    $config = config('book.settings');
     // Update the list of node types that are allowed to be added to books.
-    $allowed_types = variable_get('book_allowed_types', array('book'));
+    $allowed_types = $config->get('allowed_types');
     $key = array_search($type->old_type, $allowed_types);
 
     if ($key !== FALSE) {
       $allowed_types[$type->type] = $allowed_types[$key] ? $type->type : 0;
       unset($allowed_types[$key]);
-      variable_set('book_allowed_types', $allowed_types);
+      $config->set('allowed_types', $allowed_types);
     }
 
     // Update the setting for the "Add child page" link.
-    if (variable_get('book_child_type', 'book') == $type->old_type) {
-      variable_set('book_child_type', $type->type);
+    if ($config->get('child_type') == $type->old_type) {
+      $config->set('child_type', $type->type);
     }
+    $config->save();
   }
 }
 
diff --git a/core/modules/book/config/book.settings.yml b/core/modules/book/config/book.settings.yml
new file mode 100644
index 0000000..1d8e23f
--- /dev/null
+++ b/core/modules/book/config/book.settings.yml
@@ -0,0 +1,5 @@
+allowed_types:
+    - book
+child_type: book
+block_mode: all pages
+