diff --git a/core/modules/language/config/language.negotiation.yml b/core/modules/language/config/language.negotiation.yml
new file mode 100644
index 0000000..ed1c541
--- /dev/null
+++ b/core/modules/language/config/language.negotiation.yml
@@ -0,0 +1,2 @@
+session:
+    parameter: language
diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index a601d00..b9ec2cb 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -797,16 +797,27 @@ function language_negotiation_configure_url_form_submit($form, &$form_state) {
 
 /**
  * Builds the session language negotiation method configuration form.
+ *
+ * @see language_negotiation_configure_session_form_submit()
  */
 function language_negotiation_configure_session_form($form, &$form_state) {
   $form['language_negotiation_session_param'] = array(
     '#title' => t('Request/session parameter'),
     '#type' => 'textfield',
-    '#default_value' => variable_get('language_negotiation_session_param', 'language'),
+    '#default_value' => config('language.negotiation')->get('session.parameter'),
     '#description' => t('Name of the request/session parameter used to determine the desired language.'),
   );
 
   $form_state['redirect'] = 'admin/config/regional/language/detection';
 
-  return system_settings_form($form);
+  return system_config_form($form, $form_state);
+}
+
+/**
+ * Form submission handler for language_negotiation_configure_session_form().
+ */
+function language_negotiation_configure_session_form_submit($form, &$form_state) {
+  config('language.negotiation')
+    ->set('session.parameter', $form_state['values']['language_negotiation_session_param'])
+    ->save();
 }
diff --git a/core/modules/language/language.install b/core/modules/language/language.install
index 37f41d6..8742492 100644
--- a/core/modules/language/language.install
+++ b/core/modules/language/language.install
@@ -40,7 +40,6 @@ function language_uninstall() {
   variable_del('language_negotiation_url_part');
   variable_del('language_negotiation_url_prefixes');
   variable_del('language_negotiation_url_domains');
-  variable_del('language_negotiation_session_param');
   variable_del('language_content_type_default');
   variable_del('language_content_type_negotiation');
 
@@ -49,6 +48,8 @@ function language_uninstall() {
     variable_del("language_negotiation_methods_weight_$type");
   }
 
+  config('language.negotiation')->delete('session.parameter')->save();
+
   // Re-initialize the language system so successive calls to t() and other
   // functions will not expect languages to be present.
   drupal_language_initialize();
@@ -102,3 +103,12 @@ function language_schema() {
   );
   return $schema;
 }
+
+/**
+ * Moves language settings from variables to config.
+ */
+function language_update_8000() {
+  update_variables_to_config('language.negotiation', array(
+    'language_negotiation_session_param' => 'session.parameter',
+  ));
+}
diff --git a/core/modules/language/language.negotiation.inc b/core/modules/language/language.negotiation.inc
index 01c39a8..13a343d 100644
--- a/core/modules/language/language.negotiation.inc
+++ b/core/modules/language/language.negotiation.inc
@@ -171,7 +171,7 @@ function language_from_user($languages) {
  *   A valid language code on success, FALSE otherwise.
  */
 function language_from_session($languages) {
-  $param = variable_get('language_negotiation_session_param', 'language');
+  $param = config('language.negotiation')->get('session.parameter');
 
   // Request parameter: we need to update the session parameter only if we have
   // an authenticated user.
@@ -320,7 +320,7 @@ function language_switcher_url($type, $path) {
  * Return the session language switcher block.
  */
 function language_switcher_session($type, $path) {
-  $param = variable_get('language_negotiation_session_param', 'language');
+  $param = config('language.negotiation')->get('session.parameter');
   $language_query = isset($_SESSION[$param]) ? $_SESSION[$param] : drupal_container()->get($type)->langcode;
 
   $languages = language_list();
@@ -453,7 +453,7 @@ function language_url_rewrite_session(&$path, &$options) {
     global $user;
     if (!$user->uid) {
       $languages = language_list();
-      $query_param = check_plain(variable_get('language_negotiation_session_param', 'language'));
+      $query_param = check_plain(config('language.negotiation')->get('session.parameter'));
       $query_value = isset($_GET[$query_param]) ? check_plain($_GET[$query_param]) : NULL;
       $query_rewrite = isset($languages[$query_value]) && language_negotiation_method_enabled(LANGUAGE_NEGOTIATION_SESSION);
     }
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocaleUninstallTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocaleUninstallTest.php
index b63e8cd..9c45690 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocaleUninstallTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocaleUninstallTest.php
@@ -83,7 +83,7 @@ function testUninstallProcess() {
 
     // Change language negotiation settings.
     variable_set('language_negotiation_url_part', LANGUAGE_NEGOTIATION_URL_PREFIX);
-    variable_set('language_negotiation_session_param', TRUE);
+    config('language.negotiation')->set('session.parameter', TRUE)->save();
 
     // Uninstall Locale.
     module_disable($locale_module);
@@ -115,7 +115,7 @@ function testUninstallProcess() {
 
     // Check language negotiation method settings.
     $this->assertFalse(variable_get('language_negotiation_url_part', FALSE), t('URL language negotiation method indicator settings cleared.'));
-    $this->assertFalse(variable_get('language_negotiation_session_param', FALSE), t('Visit language negotiation method settings cleared.'));
+    $this->assertNull(config('language.negotiation')->get('session.parameter'), t('Visit language negotiation method settings cleared.'));
 
     // Check JavaScript parsed.
     $javascript_parsed_count = count(variable_get('javascript_parsed', array()));
diff --git a/core/modules/locale/locale.install b/core/modules/locale/locale.install
index 35106ae..31e30f4 100644
--- a/core/modules/locale/locale.install
+++ b/core/modules/locale/locale.install
@@ -554,11 +554,11 @@ function locale_update_8007() {
  * @ingroup config_upgrade
  */
 function locale_update_8008() {
+  // @todo Convert other variables to configuration system too.
   $variable_name_map = array(
     'locale_language_negotiation_url_part' => 'language_negotiation_url_part',
     'locale_language_negotiation_url_domains' => 'language_negotiation_url_domains',
     'locale_language_negotiation_url_prefixes' => 'language_negotiation_url_prefixes',
-    'locale_language_negotiation_session_param' => 'language_negotiation_session_param',
   );
   foreach ($variable_name_map as $deprecated_variable_name => $new_variable_name) {
     // Check if this variable is stored in the db and if so rename it.
@@ -568,6 +568,10 @@ function locale_update_8008() {
       variable_del($deprecated_variable_name);
     }
   }
+
+  update_variables_to_config('language.negotiation', array(
+    'locale_language_negotiation_session_param' => 'session.parameter',
+  ));
 }
 
 /**