diff -u b/core/modules/menu_link_content/src/Form/MenuLinkContentForm.php b/core/modules/menu_link_content/src/Form/MenuLinkContentForm.php
--- b/core/modules/menu_link_content/src/Form/MenuLinkContentForm.php
+++ b/core/modules/menu_link_content/src/Form/MenuLinkContentForm.php
@@ -213,7 +213,7 @@
   public function extractFormValues(array &$form, FormStateInterface $form_state) {
     $new_definition = array();
     $new_definition['expanded'] = !empty($form_state['values']['expanded']['value']) ? 1 : 0;
-    $new_definition['enabled'] = !empty($form_state['values']['enabled']) ? 1 : 0;
+    $new_definition['enabled'] = !empty($form_state['values']['enabled']['value']) ? 1 : 0;
     list($menu_name, $parent) = explode(':', $form_state['values']['menu_parent'], 2);
     if (!empty($menu_name)) {
       $new_definition['menu_name'] = $menu_name;
diff -u b/core/modules/menu_ui/src/Tests/MenuTest.php b/core/modules/menu_ui/src/Tests/MenuTest.php
--- b/core/modules/menu_ui/src/Tests/MenuTest.php
+++ b/core/modules/menu_ui/src/Tests/MenuTest.php
@@ -707,7 +707,7 @@
    */
   function disableMenuLink(MenuLinkContent $item) {
     $mlid = $item->id();
-    $edit['enabled[value]'] = 0;
+    $edit['enabled[value]'] = FALSE;
     $this->drupalPostForm("admin/structure/menu/item/$mlid/edit", $edit, t('Save'));
 
     // Unlike most other modules, there is no confirmation message displayed.
@@ -723,7 +723,7 @@
    */
   function enableMenuLink(MenuLinkContent $item) {
     $mlid = $item->id();
-    $edit['enabled[value]'] = 1;
+    $edit['enabled[value]'] = TRUE;
     $this->drupalPostForm("admin/structure/menu/item/$mlid/edit", $edit, t('Save'));
 
     // Verify in the database.