diff --git a/core/includes/language.inc b/core/includes/language.inc
index e0550ff..03a9b48 100644
--- a/core/includes/language.inc
+++ b/core/includes/language.inc
@@ -134,10 +134,12 @@ function language_types_info() {
  *
  * @return
  *   An array of language type names.
+ *
+ * @deprecated as of 8.0, use
+ *   \Drupal::languageManager()->getConfigurableLanguageTypes() instead.
  */
 function language_types_get_configurable() {
-  $configurable = \Drupal::config('system.language.types')->get('configurable');
-  return $configurable ? $configurable : array();
+  return \Drupal::languageManager()->getConfigurableLanguageTypes();
 }
 
 /**
diff --git a/core/lib/Drupal/Core/Language/LanguageManager.php b/core/lib/Drupal/Core/Language/LanguageManager.php
index fffbb1e..3af2df7 100644
--- a/core/lib/Drupal/Core/Language/LanguageManager.php
+++ b/core/lib/Drupal/Core/Language/LanguageManager.php
@@ -130,6 +130,7 @@ public function init() {
       return;
     }
     if ($this->isMultilingual()) {
+      // FIXME!
       // This is still assumed by various functions to be loaded.
       include_once DRUPAL_ROOT . '/core/includes/language.inc';
     }
@@ -363,6 +364,13 @@ public function getLanguageTypes() {
   /**
    * {@inheritdoc}
    */
+  public function getConfigurableLanguageTypes() {
+    return \Drupal::config('system.language.types')->get('configurable') ?: array();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function getTypeDefaults() {
     return array(
       Language::TYPE_INTERFACE => TRUE,
diff --git a/core/lib/Drupal/Core/Language/LanguageManagerInterface.php b/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
index 2ac9137..2007985 100644
--- a/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
+++ b/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
@@ -141,6 +141,18 @@ public function getFallbackCandidates($langcode = NULL, array $context = array()
   public function getLanguageTypes();
 
   /**
+   * Returns only the configurable language types.
+   *
+   * A language type maybe configurable or fixed. A fixed language type is a
+   * type whose language negotiation methods are module-defined and not altered
+   * through the user interface.
+   *
+   * @return
+   *   An array of language type names.
+   */
+  public function getConfigurableLanguageTypes();
+
+  /**
    * Returns a list of the built-in language types.
    *
    * @return array
diff --git a/core/modules/language/lib/Drupal/language/HttpKernel/PathProcessorLanguage.php b/core/modules/language/lib/Drupal/language/HttpKernel/PathProcessorLanguage.php
index f91eed3..66813fc 100644
--- a/core/modules/language/lib/Drupal/language/HttpKernel/PathProcessorLanguage.php
+++ b/core/modules/language/lib/Drupal/language/HttpKernel/PathProcessorLanguage.php
@@ -117,7 +117,7 @@ public function processOutbound($path, &$options = array(), Request $request = N
   protected function initProcessors($scope) {
     $interface = '\Drupal\Core\PathProcessor\\' . Unicode::ucfirst($scope) . 'PathProcessorInterface';
     $this->processors[$scope] = array();
-    foreach (language_types_get_configurable() as $type) {
+    foreach ($this->languageManager->getConfigurableLanguageTypes() as $type) {
       foreach ($this->languageManager->getNegotiationMethods($type) as $method_id => $method) {
         if (!isset($this->processors[$scope][$method_id])) {
           $reflector = new \ReflectionClass($method['class']);
diff --git a/core/modules/language/lib/Drupal/language/LanguageManager.php b/core/modules/language/lib/Drupal/language/LanguageManager.php
index 8e11446..fc341fa 100644
--- a/core/modules/language/lib/Drupal/language/LanguageManager.php
+++ b/core/modules/language/lib/Drupal/language/LanguageManager.php
@@ -67,7 +67,7 @@ public function getLanguageList($flags = Language::STATE_CONFIGURABLE) {
 
       // Use language module configuration if available.
       $language_ids = $this->configStorage->listAll('language.entity');
-      foreach (\Drupal::service('config.factory')->loadMultiple($language_ids) as $language_config) {
+      foreach ($this->configStorage->loadMultiple($language_ids) as $language_config) {
         $langcode = $language_config->get('id');
         $info = $language_config->get();
         $info['default'] = ($langcode == $default->id);
diff --git a/core/modules/language/tests/language_test/lib/Drupal/language_test/Plugin/LanguageNegotiation/LanguageNegotiationTest.php b/core/modules/language/tests/language_test/lib/Drupal/language_test/Plugin/LanguageNegotiation/LanguageNegotiationTest.php
index 226e1fe..615471f 100644
--- a/core/modules/language/tests/language_test/lib/Drupal/language_test/Plugin/LanguageNegotiation/LanguageNegotiationTest.php
+++ b/core/modules/language/tests/language_test/lib/Drupal/language_test/Plugin/LanguageNegotiation/LanguageNegotiationTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\language_test\Plugin\LanguageNegotiation;
 
 use Drupal\Core\Language\LanguageNegotiationMethodBase;
+use Drupal\Core\Session\AccountInterface;
 use Symfony\Component\HttpFoundation\Request;
 
 /**
@@ -31,7 +32,7 @@ class LanguageNegotiationTest extends LanguageNegotiationMethodBase {
   /**
    * {@inheritdoc}
    */
-  public function negotiateLanguage(array $languages, Request $request = NULL) {
+  public function negotiateLanguage(AccountInterface $current_user, Request $request = NULL) {
     return 'it';
   }