diff --git a/config/install/email_registration.settings.yml b/config/install/email_registration.settings.yml
new file mode 100644
index 0000000..f684df7
--- /dev/null
+++ b/config/install/email_registration.settings.yml
@@ -0,0 +1 @@
+login_with_username: FALSE
diff --git a/config/schema/email_registration.schema.yml b/config/schema/email_registration.schema.yml
new file mode 100644
index 0000000..6f390cd
--- /dev/null
+++ b/config/schema/email_registration.schema.yml
@@ -0,0 +1,7 @@
+email_registration.settings:
+  type: config_object
+  label: 'Email registration config'
+  mapping:
+    login_with_username:
+      type: boolean
+      label: 'Allow users login with e-mail or username.'
diff --git a/email_registration.info.yml b/email_registration.info.yml
index ccd35e7..8cdb48f 100644
--- a/email_registration.info.yml
+++ b/email_registration.info.yml
@@ -1,4 +1,10 @@
 name: Email Registration
 type: module
 description: 'Allows users to register with an e-mail address as their username.'
-core: 8.x
+# core: 8.x
+
+# Information added by Drupal.org packaging script on 2016-07-15
+version: '8.x-1.0-rc3'
+core: '8.x'
+project: 'email_registration'
+datestamp: 1468594748
diff --git a/email_registration.links.menu.yml b/email_registration.links.menu.yml
new file mode 100644
index 0000000..0127586
--- /dev/null
+++ b/email_registration.links.menu.yml
@@ -0,0 +1,5 @@
+email_registration.settings:
+  title: 'Email Registration settings'
+  parent: user.admin_index
+  description: 'Control the settings of the Email Registration module'
+  route_name: email_registration.settings
diff --git a/email_registration.module b/email_registration.module
index 2a1e42a..ed6f97c 100644
--- a/email_registration.module
+++ b/email_registration.module
@@ -9,6 +9,7 @@ use Drupal\Component\Utility\Unicode;
 use Drupal\user\UserInterface;
 use Drupal\Core\Render\Element\Email;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Url;
 
 /**
  * Implements hook_ENTITY_TYPE_insert().
@@ -44,12 +45,7 @@ function email_registration_user_insert(UserInterface $account) {
   // Ensure whatever name we have is unique.
   $new_name = email_registration_unique_username($new_name, $account->id());
 
-  $account->setUsername($new_name);
-  if ($account->isValidationRequired() && !$account->validate()) {
-    \Drupal::logger('email_registration')->error('Email registration failed setting the new name on user @id.', ['@id' => $account->id()]);
-    return;
-  }
-  $account->save();
+  $account->setUsername($new_name)->save();
 }
 
 /**
@@ -138,12 +134,14 @@ function email_registration_form_user_pass_alter(&$form, FormStateInterface $for
  * Implements hook_form_FORM_ID_alter().
  */
 function email_registration_form_user_login_form_alter(&$form, FormStateInterface $form_state) {
-  $form['name']['#title'] = t('E-mail');
-  $form['name']['#description'] = t('Enter your e-mail address.');
+  $config = \Drupal::config('email_registration.settings');
+  $login_with_username = $config->get('login_with_username');
+  $form['name']['#title']  = $login_with_username ? t('E-mail or username') : t('E-mail');
+  $form['name']['#description']  = $login_with_username ? t('Enter your e-mail address or username.') : t('Enter your e-mail address.');;
   $form['name']['#element_validate'][] = 'email_registration_user_login_validate';
   $form['pass']['#description'] = t('Enter the password that accompanies your e-mail.');
   // Allow client side validation of input format.
-  $form['name']['#type'] = 'email';
+  $form['name']['#type'] = !$login_with_username ? 'email' : 'textfield';
   $form['name']['#maxlength'] = Email::EMAIL_MAX_LENGTH;
 }
 
@@ -154,9 +152,16 @@ function email_registration_form_user_login_form_alter(&$form, FormStateInterfac
  */
 function email_registration_user_login_validate($form, FormStateInterface $form_state) {
   $mail = $form_state->getValue('name');
-  if (!empty($mail) && ($user = user_load_by_mail($mail))) {
-    // Keep the email value in form state for further validation.
-    $form_state->setValue('name', $user->getAccountName());
+  if (!empty($mail)) {
+    $config = \Drupal::config('email_registration.settings');
+    if ($user = user_load_by_mail($mail)) {
+      $form_state->setValue('name', $user->getAccountName());
+    }
+    elseif (!$config->get('login_with_username')) {
+      $user_input = $form_state->getUserInput();
+      $query = isset($user_input['name']) ? array('name' => $user_input['name']) : array();
+      $form_state->setErrorByName('name', t('Unrecognized e-mail address or password. <a href=":password">Forgot your password?</a>', array(':password' => Url::fromRoute('user.pass', [], array('query' => $query))->toString())));
+    }
   }
 }
 
@@ -166,3 +171,27 @@ function email_registration_user_login_validate($form, FormStateInterface $form_
 function email_registration_form_user_form_alter(&$form, FormStateInterface $form_state) {
   $form['account']['name']['#title'] = t('Display name');
 }
+
+/**
+ * Implements hook_form_FORM_ID_alter().
+ */
+function email_registration_form_user_admin_settings_alter(&$form, &$form_state) {
+  $config = \Drupal::config('email_registration.settings');
+  $form['registration_cancellation']['login_with_username'] = array(
+    '#type' => 'checkbox',
+    '#title' => t('Allow users login with e-mail or username.'),
+    '#description' => t('Allow users to login with their username in addition to their e-mail.'),
+    '#default_value' => $config->get('login_with_username'),
+  );
+  $form['#submit'][] = 'email_registration_form_user_admin_settings_submit';
+}
+
+/**
+ * Submit function for user_admin_settings to save our variable.
+ *
+ * @see email_registration_form_user_admin_settings_alter().
+ */
+function email_registration_form_user_admin_settings_submit(array &$form, FormStateInterface $form_state) {
+  $config = \Drupal::configFactory()->getEditable('email_registration.settings');
+  $config->set('login_with_username', $form_state->getValue('login_with_username'))->save();
+}
diff --git a/email_registration.permissions.yml b/email_registration.permissions.yml
new file mode 100644
index 0000000..4aa5727
--- /dev/null
+++ b/email_registration.permissions.yml
@@ -0,0 +1,3 @@
+administer email registration:
+  title: 'Administer Email Registration'
+  restrict access: true
diff --git a/email_registration.routing.yml b/email_registration.routing.yml
new file mode 100644
index 0000000..394bd2a
--- /dev/null
+++ b/email_registration.routing.yml
@@ -0,0 +1,7 @@
+email_registration.settings:
+  path: '/admin/config/people/email_registration'
+  defaults:
+    _title: 'Email Registration settings'
+    _form: '\Drupal\email_registration\Form\SettingsForm'
+  requirements:
+    _permission: 'administer email registration'
diff --git a/src/Form/SettingsForm.php b/src/Form/SettingsForm.php
new file mode 100644
index 0000000..589b526
--- /dev/null
+++ b/src/Form/SettingsForm.php
@@ -0,0 +1,54 @@
+<?php
+
+namespace Drupal\email_registration\Form;
+
+use Drupal\Core\Form\ConfigFormBase;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Form builder for the email registration settings form.
+ */
+class SettingsForm extends ConfigFormBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'email_registration_settings_form';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getEditableConfigNames() {
+    return ['email_registration.settings'];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state) {
+    $config = $this->config('email_registration.settings');
+
+    $form['login_with_username'] = array(
+      '#type' => 'checkbox',
+      '#title' => $this->t('Allow users login with e-mail or username.'),
+      '#default_value' => $config->get('login_with_username'),
+      '#description' => $this->t('Allow users to login with their username in addition to their e-mail.'),
+    );
+
+    return parent::buildForm($form, $form_state);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    parent::submitForm($form, $form_state);
+    $config = $this->config('email_registration.settings');
+
+    $config->set('login_with_username', $form_state->getValue('login_with_username'));
+    $config->save();
+  }
+
+}
diff --git a/src/Tests/EmailRegistrationTestCase.php b/src/Tests/EmailRegistrationTestCase.php
index 776ea76..6e755cd 100644
--- a/src/Tests/EmailRegistrationTestCase.php
+++ b/src/Tests/EmailRegistrationTestCase.php
@@ -23,6 +23,7 @@ class EmailRegistrationTestCase extends WebTestBase {
    */
   public function testRegistration() {
     $user_config = $this->container->get('config.factory')->getEditable('user.settings');
+    $email_registration_config = $this->container->get('config.factory')->getEditable('email_registration.settings');
     $user_config
       ->set('verify_mail', FALSE)
       ->set('register', USER_REGISTER_VISITORS)
@@ -49,6 +50,21 @@ class EmailRegistrationTestCase extends WebTestBase {
 
     // Now try the immediate login.
     $this->drupalLogout();
+
+    // Try to login with just username, should fail by default.
+    $login = array(
+      'name' => $name,
+      'pass' => $pass,
+    );
+    $this->drupalPostForm('user/login', $login, t('Log in'));
+    $this->assertFieldByXpath('//div[contains(@class, "error")]', NULL, t('When login_with_username is false, a user cannot login with just their username.'));
+
+    // Set login_with_username to TRUE and try to login with just username.
+    $email_registration_config->set('login_with_username', TRUE)->save();
+    $this->drupalPostForm('user/login', $login, t('Log in'));
+    $this->assertRaw('<title>' . $name . ' | Drupal</title>', t('When login_with_username is true, a user can login with just their username.'));
+    $this->drupalLogout();
+
     $user_config
       ->set('verify_mail', FALSE)
       ->save();