diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 596a47b..dd8a0a5 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -207,7 +207,7 @@ const LANGUAGE_MULTIPLE = 'mul';
  * The language code used when referring to all languages.
  *
  */
-const LANGUAGE_ALL = 'all';
+const LANGUAGE_ALL = TRUE;
 
 /**
  * The type of language used to define the content language.
@@ -2660,8 +2660,8 @@ function language_multilingual() {
  * Returns a list of configured languages.
  *
  * @param $all
- *   (optional) A flag depending on the need for locked
- *   languages in the returned list.
+ *   (optional) A flag depending on the need for locked languages in the
+ *   returned list.
  *
  * @return
  *   An associative array of languages, keyed by the language code, ordered by
@@ -2757,7 +2757,7 @@ function language_locked_languages($weight = 20) {
  *   A fully-populated language object or FALSE.
  */
 function language_load($langcode) {
-  $languages = language_list(TRUE);
+  $languages = language_list(LANGUAGE_ALL);
   return isset($languages[$langcode]) ? $languages[$langcode] : FALSE;
 }
 
diff --git a/core/modules/block/block.admin.inc b/core/modules/block/block.admin.inc
index f5107c9..aa018da 100644
--- a/core/modules/block/block.admin.inc
+++ b/core/modules/block/block.admin.inc
@@ -419,7 +419,7 @@ function block_admin_configure($form, &$form_state, $module, $delta) {
     }
 
     // Fetch languages.
-    $languages = language_list(TRUE);
+    $languages = language_list(LANGUAGE_ALL);
     foreach ($languages as $language) {
       // @TODO $language->name is not wrapped with t(), it should be replaced
       // by CMI translation implementation.
diff --git a/core/modules/field/field.multilingual.inc b/core/modules/field/field.multilingual.inc
index aa97e6f..3b92c99 100644
--- a/core/modules/field/field.multilingual.inc
+++ b/core/modules/field/field.multilingual.inc
@@ -169,7 +169,7 @@ function _field_language_suggestion($available_langcodes, $langcode_suggestion,
  *   An array of language codes.
  */
 function field_content_languages() {
-  return array_keys(language_list(TRUE));
+  return array_keys(language_list(LANGUAGE_ALL));
 }
 
 /**
diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index b543971..a601d00 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -12,7 +12,7 @@ use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
  */
 function language_admin_overview_form($form, &$form_state) {
   drupal_static_reset('language_list');
-  $languages = language_list(TRUE);
+  $languages = language_list(LANGUAGE_ALL);
   $default = language_default();
 
   $form['languages'] = array(
@@ -164,7 +164,7 @@ function theme_language_admin_overview_form_table($variables) {
  * Process language overview form submissions, updating existing languages.
  */
 function language_admin_overview_form_submit($form, &$form_state) {
-  $languages = language_list(TRUE);
+  $languages = language_list(LANGUAGE_ALL);
   $old_default = language_default();
 
   foreach ($languages as $langcode => $language) {
diff --git a/core/modules/language/language.module b/core/modules/language/language.module
index 73f40dd..46ba812 100644
--- a/core/modules/language/language.module
+++ b/core/modules/language/language.module
@@ -214,7 +214,7 @@ function language_save($language) {
  *   TRUE if language is successfully deleted. Otherwise FALSE.
  */
 function language_delete($langcode) {
-  $languages = language_list(TRUE);
+  $languages = language_list(LANGUAGE_ALL);
   if (isset($languages[$langcode]) && !$languages[$langcode]->locked) {
     $language = $languages[$langcode];
 
diff --git a/core/modules/node/node.admin.inc b/core/modules/node/node.admin.inc
index 1897c8b..1bb4547 100644
--- a/core/modules/node/node.admin.inc
+++ b/core/modules/node/node.admin.inc
@@ -106,7 +106,7 @@ function node_filters() {
 
   // Language filter if language support is present.
   if (language_multilingual()) {
-    $languages = language_list(TRUE);
+    $languages = language_list(LANGUAGE_ALL);
     foreach ($languages as $langcode => $language) {
       // Make locked languages appear special in the list.
       $language_options[$langcode] = $language->locked ? t('- @name -', array('@name' => $language->name)) : $language->name;
@@ -476,7 +476,7 @@ function node_admin_nodes() {
   $nodes = node_load_multiple($nids);
 
   // Prepare the list of nodes.
-  $languages = language_list(TRUE);
+  $languages = language_list(LANGUAGE_ALL);
   $destination = drupal_get_destination();
   $options = array();
   foreach ($nodes as $node) {
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index 03f4ea9..75a7417 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -2658,7 +2658,7 @@ function node_form_search_form_alter(&$form, $form_state) {
 
     // Languages:
     $language_options = array();
-    foreach (language_list(TRUE) as $langcode => $language) {
+    foreach (language_list(LANGUAGE_ALL) as $langcode => $language) {
       // Make locked languages appear special in the list.
       $language_options[$langcode] = $language->locked ? t('- @name -', array('@name' => $language->name)) : $language->name;
     }
diff --git a/core/modules/node/node.pages.inc b/core/modules/node/node.pages.inc
index b877893..2e5ecee 100644
--- a/core/modules/node/node.pages.inc
+++ b/core/modules/node/node.pages.inc
@@ -187,7 +187,7 @@ function node_form($form, &$form_state, Node $node) {
   $form['#node'] = $node;
 
   if (variable_get('node_type_language_' . $node->type, 0) && module_exists('language')) {
-    $languages = language_list(TRUE);
+    $languages = language_list(LANGUAGE_ALL);
     $language_options = array();
     foreach ($languages as $langcode => $language) {
       // Make locked languages appear special in the list.
diff --git a/core/modules/system/lib/Drupal/system/Tests/Upgrade/LanguageUpgradePathTest.php b/core/modules/system/lib/Drupal/system/Tests/Upgrade/LanguageUpgradePathTest.php
index 5049ab1..39e6982 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Upgrade/LanguageUpgradePathTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Upgrade/LanguageUpgradePathTest.php
@@ -40,7 +40,7 @@ class LanguageUpgradePathTest extends UpgradePathTestBase {
 
     // Ensure Catalan was properly upgraded to be the new default language.
     $this->assertTrue(language_default()->langcode == 'ca', t('Catalan is the default language'));
-    $languages = language_list(TRUE);
+    $languages = language_list(LANGUAGE_ALL);
     foreach ($languages as $language) {
       $this->assertTrue($language->default == ($language->langcode == 'ca'), t('@language default property properly set', array('@language' => $language->name)));
     }
diff --git a/core/modules/translation/translation.module b/core/modules/translation/translation.module
index 49ceea5..0298097 100644
--- a/core/modules/translation/translation.module
+++ b/core/modules/translation/translation.module
@@ -197,7 +197,7 @@ function translation_node_view(Node $node, $view_mode) {
   // If the site has no translations or is not multilingual we have no content
   // translation links to display.
   if (isset($node->tnid) && language_multilingual() && $translations = translation_node_get_translations($node->tnid)) {
-    $languages = language_list(TRUE);
+    $languages = language_list(LANGUAGE_ALL);
 
     // There might be a language provider enabled defining custom language
     // switch links which need to be taken into account while generating the