diff -u b/core/modules/user/lib/Drupal/user/RoleStorageController.php b/core/modules/user/lib/Drupal/user/RoleStorageController.php
--- b/core/modules/user/lib/Drupal/user/RoleStorageController.php
+++ b/core/modules/user/lib/Drupal/user/RoleStorageController.php
@@ -15,22 +15,24 @@
  */
 class RoleStorageController extends ConfigStorageController {
 
-  /**
-   * Overrides ConfigStorageController::save().
-   */
-  public function save(EntityInterface $entity) {
-    // Prevent leading and trailing spaces in role names.
-    $entity->label = trim($entity->label);
-
-    if (!isset($entity->weight)) {
-      $roles = entity_load_multiple('entity_roles');
+  public function create(array $values) {
+    $entity = parent::create($values);
+    $roles = entity_load_multiple('user_role');
+    if (count($roles)) {
       // Set a role weight to make this new role last.
       $max = array_reduce($roles, function($max, $entity) {
         return $max > $entity->weight ? $max : $entity->weight;
       });
       $entity->weight = $max + 1;
     }
-
+    return $entity;
+  }
+  /**
+   * Overrides ConfigStorageController::save().
+   */
+  public function save(EntityInterface $entity) {
+    // Prevent leading and trailing spaces in role names.
+    $entity->label = trim($entity->label);
     return parent::save($entity);
   }
 
diff -u b/core/modules/user/user.admin.inc b/core/modules/user/user.admin.inc
--- b/core/modules/user/user.admin.inc
+++ b/core/modules/user/user.admin.inc
@@ -834,9 +834,8 @@
   $form['roles'] = array(
     '#tree' => TRUE,
   );
-  $max_weight = 0;
+
   foreach ($roles as $rid => $role) {
-    $max_weight = max($max_weight, $role->weight);
     $form['roles'][$rid]['#role'] = $role;
     $form['roles'][$rid]['#weight'] = $role->weight;
     $form['roles'][$rid]['name'] = array(
@@ -870,7 +869,6 @@
   $add_role = entity_create('user_role', array(
     'id' => NULL,
     'label' => NULL,
-    'weight' => $max_weight + 1,
   ));
   $add_form = user_admin_role(array(), $form_state, $add_role);
   $add_form['actions']['submit']['#submit'] = array('user_admin_role_submit');