diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index 2c8e7af06f5..79dc5d16913 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -24,146 +24,6 @@ function language_admin_predefined_list() {
   return $predefined;
 }
 
-/**
- * Builds the configuration form for language negotiation.
- *
- * @deprecated Use \Drupal\language\Form\LanguageForm::negotiation()
- */
-function language_negotiation_configure_form() {
-  language_negotiation_include();
-
-  $form = array(
-    '#submit' => array('language_negotiation_configure_form_submit'),
-    '#theme' => 'language_negotiation_configure_form',
-    '#language_types_info' => language_types_info(),
-    '#language_negotiation_info' => language_negotiation_info(),
-  );
-  $form['#language_types'] = array();
-  $configurable = \Drupal::config('system.language.types')->get('configurable');
-  foreach ($form['#language_types_info'] as $type => $info) {
-    // Show locked language types only if they are configurable.
-    if (empty($info['locked']) || in_array($type, $configurable)) {
-      $form['#language_types'][] = $type;
-    }
-  }
-  foreach ($form['#language_types'] as $type) {
-    language_negotiation_configure_form_table($form, $type);
-  }
-
-  $form['actions'] = array('#type' => 'actions');
-  $form['actions']['submit'] = array(
-    '#type' => 'submit',
-    '#value' => t('Save settings'),
-  );
-
-  return $form;
-}
-
-/**
- * Builds a language negotiation method configuration table.
- */
-function language_negotiation_configure_form_table(&$form, $type) {
-  $info = $form['#language_types_info'][$type];
-
-  $table_form = array(
-    '#title' => t('@type language detection', array('@type' => $info['name'])),
-    '#tree' => TRUE,
-    '#description' => $info['description'],
-    '#language_negotiation_info' => array(),
-    '#show_operations' => FALSE,
-    'weight' => array('#tree' => TRUE),
-  );
-  // Only show configurability checkbox for the unlocked language types.
-  if (empty($info['locked'])) {
-    $configurable = \Drupal::config('system.language.types')->get('configurable');
-    $table_form['configurable'] = array(
-      '#type' => 'checkbox',
-      '#title' => t('Customize %language_name language detection to differ from User interface text language detection settings.', array('%language_name' => $info['name'])),
-      '#default_value' => in_array($type, $configurable),
-      '#attributes' => array('class' => array('language-customization-checkbox')),
-      '#attached' => array(
-        'library' => array(
-          array('language', 'language.admin')
-        ),
-      ),
-    );
-  }
-
-  $negotiation_info = $form['#language_negotiation_info'];
-  $enabled_methods = variable_get("language_negotiation_$type", array());
-  $methods_weight = variable_get("language_negotiation_methods_weight_$type", array());
-
-  // Add missing data to the methods lists.
-  foreach ($negotiation_info as $method_id => $method) {
-    if (!isset($methods_weight[$method_id])) {
-      $methods_weight[$method_id] = isset($method['weight']) ? $method['weight'] : 0;
-    }
-  }
-
-  // Order methods list by weight.
-  asort($methods_weight);
-
-  foreach ($methods_weight as $method_id => $weight) {
-    // A language method might be no more available if the defining module has
-    // been disabled after the last configuration saving.
-    if (!isset($negotiation_info[$method_id])) {
-      continue;
-    }
-
-    $enabled = isset($enabled_methods[$method_id]);
-    $method = $negotiation_info[$method_id];
-
-    // List the method only if the current type is defined in its 'types' key.
-    // If it is not defined default to all the configurable language types.
-    $types = array_flip(isset($method['types']) ? $method['types'] : $form['#language_types']);
-
-    if (isset($types[$type])) {
-      $table_form['#language_negotiation_info'][$method_id] = $method;
-      $method_name = check_plain($method['name']);
-
-      $table_form['weight'][$method_id] = array(
-        '#type' => 'weight',
-        '#title' => t('Weight for !title language detection method', array('!title' => drupal_strtolower($method_name))),
-        '#title_display' => 'invisible',
-        '#default_value' => $weight,
-        '#attributes' => array('class' => array("language-method-weight-$type")),
-        '#delta' => 20,
-      );
-
-      $table_form['title'][$method_id] = array('#markup' => $method_name);
-
-      $table_form['enabled'][$method_id] = array(
-        '#type' => 'checkbox',
-        '#title' => t('Enable !title language detection method', array('!title' => drupal_strtolower($method_name))),
-        '#title_display' => 'invisible',
-        '#default_value' => $enabled,
-      );
-      if ($method_id === LANGUAGE_NEGOTIATION_SELECTED) {
-        $table_form['enabled'][$method_id]['#default_value'] = TRUE;
-        $table_form['enabled'][$method_id]['#attributes'] = array('disabled' => 'disabled');
-      }
-
-      $table_form['description'][$method_id] = array('#markup' => filter_xss_admin($method['description']));
-
-      $config_op = array();
-      if (isset($method['config'])) {
-        $config_op['configure'] = array(
-          'title' => t('Configure'),
-          'href' => $method['config'],
-        );
-        // If there is at least one operation enabled show the operation column.
-        $table_form['#show_operations'] = TRUE;
-      }
-      $table_form['operation'][$method_id] = array(
-       '#type' => 'operations',
-       '#links' => $config_op,
-      );
-    }
-  }
-
-  $form[$type] = $table_form;
-}
-
 /**
  * Returns HTML for the language negotiation configuration form.
  *
@@ -238,59 +98,6 @@ function theme_language_negotiation_configure_form($variables) {
   return $output;
 }
 
-/**
- * Submit handler for language negotiation settings.
- */
-function language_negotiation_configure_form_submit($form, &$form_state) {
-  $configurable_types = $form['#language_types'];
-
-  $stored_values = \Drupal::config('system.language.types')->get('configurable');
-  $customized = array();
-  $method_weights_type = array();
-
-  foreach ($configurable_types as $type) {
-    $customized[$type] = in_array($type, $stored_values);
-    $method_weights = array();
-    $enabled_methods = $form_state['values'][$type]['enabled'];
-    $enabled_methods[LANGUAGE_NEGOTIATION_SELECTED] = TRUE;
-    $method_weights_input = $form_state['values'][$type]['weight'];
-    if (isset($form_state['values'][$type]['configurable'])) {
-      $customized[$type] = !empty($form_state['values'][$type]['configurable']);
-    }
-
-    foreach ($method_weights_input as $method_id => $weight) {
-      if ($enabled_methods[$method_id]) {
-        $method_weights[$method_id] = $weight;
-      }
-    }
-
-    $method_weights_type[$type] = $method_weights;
-    variable_set("language_negotiation_methods_weight_$type", $method_weights_input);
-  }
-
-  // Update non-configurable language types and the related language negotiation
-  // configuration.
-  language_types_set(array_keys(array_filter($customized)));
-
-  // Update the language negotiations after setting the configurability.
-  foreach ($method_weights_type as $type => $method_weights) {
-    language_negotiation_set($type, $method_weights);
-  }
-
-  // Clear block definitions cache since the available blocks and their names
-  // may have been changed based on the configurable types.
-  if (\Drupal::moduleHandler()->moduleExists('block')) {
-    // If there is an active language switcher for a language type that has been
-    // made not configurable, deactivate it first.
-    $non_configurable = array_keys(array_diff($customized, array_filter($customized)));
-    _language_disable_language_switcher($non_configurable);
-    \Drupal::service('plugin.manager.block')->clearCachedDefinitions();
-  }
-
-  $form_state['redirect_route']['route_name'] = 'language.negotiation';
-  drupal_set_message(t('Language negotiation configuration saved.'));
-}
-
 /**
  * Theme browser configuration form as table.
  *
diff --git a/core/modules/language/language.module b/core/modules/language/language.module
index ddd0cd201c5..07a4aad7a4a 100644
--- a/core/modules/language/language.module
+++ b/core/modules/language/language.module
@@ -112,6 +112,7 @@ function language_theme() {
   return array(
     'language_negotiation_configure_form' => array(
       'render element' => 'form',
+      'file' => 'language.admin.inc',
     ),
     'language_negotiation_configure_browser_form_table' => array(
       'render element' => 'form',
diff --git a/core/modules/language/language.routing.yml b/core/modules/language/language.routing.yml
index 4308ae0a841..cda5754ddd4 100644
--- a/core/modules/language/language.routing.yml
+++ b/core/modules/language/language.routing.yml
@@ -54,7 +54,7 @@ language.delete:
 language.negotiation:
   path: '/admin/config/regional/language/detection'
   defaults:
-    _content: '\Drupal\language\Form\LanguageForm::negotiation'
+    _form: '\Drupal\language\Form\NegotiationConfigureForm'
     _title: 'Detection and selection'
   requirements:
     _permission: 'administer languages'
diff --git a/core/modules/language/lib/Drupal/language/Form/LanguageForm.php b/core/modules/language/lib/Drupal/language/Form/LanguageForm.php
deleted file mode 100644
index 9194c6b7a27..00000000000
--- a/core/modules/language/lib/Drupal/language/Form/LanguageForm.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-/**
- * @file
- * Contains \Drupal\language\Form\LanguageForm.
- */
-
-namespace Drupal\language\Form;
-
-/**
- * Temporary form controller for language module.
- */
-class LanguageForm {
-
-  /**
-   * Wraps language_negotiation_configure_form().
-   *
-   * @todo Remove language_negotiation_configure_form().
-   */
-  public function negotiation() {
-    module_load_include('admin.inc', 'language');
-    return drupal_get_form('language_negotiation_configure_form');
-  }
-
-}
diff --git a/core/modules/language/lib/Drupal/language/Form/NegotiationConfigureForm.php b/core/modules/language/lib/Drupal/language/Form/NegotiationConfigureForm.php
new file mode 100644
index 00000000000..01dec5bbcf7
--- /dev/null
+++ b/core/modules/language/lib/Drupal/language/Form/NegotiationConfigureForm.php
@@ -0,0 +1,293 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Language\Form\NegotiationConfigureForm.
+ */
+
+namespace Drupal\language\Form;
+
+use Drupal\block\Plugin\Type\BlockManager;
+use Drupal\Component\Utility\String;
+use Drupal\Component\Utility\Unicode;
+use Drupal\Component\Utility\Xss;
+use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Form\FormBase;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Configure the selected language negotiation method for this site.
+ */
+class NegotiationConfigureForm extends FormBase {
+
+  /**
+   * Stores the configuration object for system.language.types.
+   *
+   * @var \Drupal\Core\Config\Config
+   */
+  protected $languageTypesConfig;
+
+  /**
+   * The block manager.
+   *
+   * @var \Drupal\block\Plugin\Type\BlockManager
+   */
+  protected $blockManager;
+
+  /**
+   * The module handler.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
+  /**
+   * Constructs a NegotiationConfigureForm object.
+   *
+   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   *   The factory for configuration objects.
+   * @param \Drupal\block\Plugin\Type\BlockManager $block_manager
+   *   The block manager, or NULL if not available.
+   */
+  public function __construct(ConfigFactory $config_factory, BlockManager $block_manager = NULL) {
+    $this->languageTypesConfig = $config_factory->get('system.language.types');
+    $this->blockManager = $block_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('config.factory'),
+      $container->has('plugin.manager.block') ? $container->get('plugin.manager.block') : NULL
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormID() {
+    return 'language_negotiation_configure_form';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, array &$form_state) {
+    language_negotiation_include();
+
+    $configurable = $this->languageTypesConfig->get('configurable');
+
+    $form = array(
+      '#theme' => 'language_negotiation_configure_form',
+      '#language_types_info' => language_types_info(),
+      '#language_negotiation_info' => language_negotiation_info(),
+    );
+    $form['#language_types'] = array();
+
+    foreach ($form['#language_types_info'] as $type => $info) {
+      // Show locked language types only if they are configurable.
+      if (empty($info['locked']) || in_array($type, $configurable)) {
+        $form['#language_types'][] = $type;
+      }
+    }
+
+    foreach ($form['#language_types'] as $type) {
+      $this->configureFormTable($form, $type);
+    }
+
+    $form['actions'] = array('#type' => 'actions');
+    $form['actions']['submit'] = array(
+      '#type' => 'submit',
+      '#value' => $this->t('Save settings'),
+    );
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, array &$form_state) {
+    language_negotiation_include();
+    $configurable_types = $form['#language_types'];
+
+    $stored_values = $this->languageTypesConfig->get('configurable');
+    $customized = array();
+    $method_weights_type = array();
+
+    foreach ($configurable_types as $type) {
+      $customized[$type] = in_array($type, $stored_values);
+      $method_weights = array();
+      $enabled_methods = $form_state['values'][$type]['enabled'];
+      $enabled_methods[LANGUAGE_NEGOTIATION_SELECTED] = TRUE;
+      $method_weights_input = $form_state['values'][$type]['weight'];
+      if (isset($form_state['values'][$type]['configurable'])) {
+        $customized[$type] = !empty($form_state['values'][$type]['configurable']);
+      }
+
+      foreach ($method_weights_input as $method_id => $weight) {
+        if ($enabled_methods[$method_id]) {
+          $method_weights[$method_id] = $weight;
+        }
+      }
+
+      $method_weights_type[$type] = $method_weights;
+      // @todo convert this to config.
+      variable_set("language_negotiation_methods_weight_$type", $method_weights_input);
+    }
+
+    // Update non-configurable language types and the related language
+    // negotiation configuration.
+    language_types_set(array_keys(array_filter($customized)));
+
+    // Update the language negotiations after setting the configurability.
+    foreach ($method_weights_type as $type => $method_weights) {
+      language_negotiation_set($type, $method_weights);
+    }
+
+    // Clear block definitions cache since the available blocks and their names
+    // may have been changed based on the configurable types.
+    if ($this->blockManager) {
+      // If there is an active language switcher for a language type that has
+      // been made not configurable, deactivate it first.
+      $non_configurable = array_keys(array_diff($customized, array_filter($customized)));
+      $this->disableLanguageSwitcher($non_configurable);
+      $this->blockManager->clearCachedDefinitions();
+    }
+
+    $form_state['redirect_route']['route_name'] = 'language.negotiation';
+    drupal_set_message($this->t('Language negotiation configuration saved.'));
+  }
+
+  /**
+   * Builds a language negotiation method configuration table.
+   *
+   * @param array $form
+   *   The language negotiation configuration form.
+   * @param string $type
+   *   The language type to generate the table for.
+   */
+  protected function configureFormTable(array &$form, $type)  {
+    $info = $form['#language_types_info'][$type];
+
+    $table_form = array(
+      '#title' => $this->t('@type language detection', array('@type' => $info['name'])),
+      '#tree' => TRUE,
+      '#description' => $info['description'],
+      '#language_negotiation_info' => array(),
+      '#show_operations' => FALSE,
+      'weight' => array('#tree' => TRUE),
+    );
+    // Only show configurability checkbox for the unlocked language types.
+    if (empty($info['locked'])) {
+      $configurable = $this->languageTypesConfig->get('configurable');
+      $table_form['configurable'] = array(
+        '#type' => 'checkbox',
+        '#title' => $this->t('Customize %language_name language detection to differ from User interface text language detection settings.', array('%language_name' => $info['name'])),
+        '#default_value' => in_array($type, $configurable),
+        '#attributes' => array('class' => array('language-customization-checkbox')),
+        '#attached' => array(
+          'library' => array(
+            array('language', 'language.admin')
+          ),
+        ),
+      );
+    }
+
+    $negotiation_info = $form['#language_negotiation_info'];
+    $enabled_methods = variable_get("language_negotiation_$type", array());
+    $methods_weight = variable_get("language_negotiation_methods_weight_$type", array());
+
+    // Add missing data to the methods lists.
+    foreach ($negotiation_info as $method_id => $method) {
+      if (!isset($methods_weight[$method_id])) {
+        $methods_weight[$method_id] = isset($method['weight']) ? $method['weight'] : 0;
+      }
+    }
+
+    // Order methods list by weight.
+    asort($methods_weight);
+
+    foreach ($methods_weight as $method_id => $weight) {
+      // A language method might be no more available if the defining module has
+      // been disabled after the last configuration saving.
+      if (!isset($negotiation_info[$method_id])) {
+        continue;
+      }
+
+      $enabled = isset($enabled_methods[$method_id]);
+      $method = $negotiation_info[$method_id];
+
+      // List the method only if the current type is defined in its 'types' key.
+      // If it is not defined default to all the configurable language types.
+      $types = array_flip(isset($method['types']) ? $method['types'] : $form['#language_types']);
+
+      if (isset($types[$type])) {
+        $table_form['#language_negotiation_info'][$method_id] = $method;
+        $method_name = String::checkPlain($method['name']);
+
+        $table_form['weight'][$method_id] = array(
+          '#type' => 'weight',
+          '#title' => $this->t('Weight for !title language detection method', array('!title' => Unicode::strtolower($method_name))),
+          '#title_display' => 'invisible',
+          '#default_value' => $weight,
+          '#attributes' => array('class' => array("language-method-weight-$type")),
+          '#delta' => 20,
+        );
+
+        $table_form['title'][$method_id] = array('#markup' => $method_name);
+
+        $table_form['enabled'][$method_id] = array(
+          '#type' => 'checkbox',
+          '#title' => $this->t('Enable !title language detection method', array('!title' => Unicode::strtolower($method_name))),
+          '#title_display' => 'invisible',
+          '#default_value' => $enabled,
+        );
+        if ($method_id === LANGUAGE_NEGOTIATION_SELECTED) {
+          $table_form['enabled'][$method_id]['#default_value'] = TRUE;
+          $table_form['enabled'][$method_id]['#attributes'] = array('disabled' => 'disabled');
+        }
+
+        $table_form['description'][$method_id] = array('#markup' => Xss::filterAdmin($method['description']));
+
+        $config_op = array();
+        if (isset($method['config'])) {
+          $config_op['configure'] = array(
+            'title' => $this->t('Configure'),
+            'href' => $method['config'],
+          );
+          // If there is at least one operation enabled show the operation
+          // column.
+          $table_form['#show_operations'] = TRUE;
+        }
+        $table_form['operation'][$method_id] = array(
+         '#type' => 'operations',
+         '#links' => $config_op,
+        );
+      }
+    }
+    $form[$type] = $table_form;
+  }
+
+  /**
+   * Disables the language switcher blocks.
+   *
+   * @param array $language_types
+   *   An array containing all language types whose language switchers need to
+   *   be disabled.
+   */
+  protected function disableLanguageSwitcher(array $language_types) {
+    $blocks = _block_rehash();
+    foreach ($language_types as $language_type) {
+      foreach ($blocks as $block) {
+        if (strpos($block->id, 'language_switcher_' . substr($language_type, 9)) !== FALSE) {
+          $block->delete();
+        }
+      }
+    }
+  }
+
+}