diff --git a/core/includes/update.inc b/core/includes/update.inc
index 1416fe0..2e078e2 100644
--- a/core/includes/update.inc
+++ b/core/includes/update.inc
@@ -693,7 +695,7 @@ function update_replace_permissions($replace) {
  *   It can be: LanguageInterface::STATE_CONFIGURABLE,
  *   LanguageInterface::STATE_LOCKED, or LanguageInterface::STATE_ALL.
  *
- * @return array
+ * @return \Drupal\Core\Language\LanguageInterface[]
  *   An associative array of languages, keyed by the language code, ordered by
  *   weight ascending and name ascending.
  */
diff --git a/core/lib/Drupal/Core/Language/LanguageManagerInterface.php b/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
index fb1768b..c29dd33 100644
--- a/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
+++ b/core/lib/Drupal/Core/Language/LanguageManagerInterface.php
@@ -136,7 +136,7 @@ public function getLanguageName($langcode);
    *   (optional) An integer value that is used as the start value for the
    *   weights of the locked languages.
    *
-   * @return array
+   * @return \Drupal\Core\Language\LanguageInterface[]
    *   An array of language objects.
    */
   public function getDefaultLockedLanguages($weight = 0);
diff --git a/core/modules/language/src/ConfigurableLanguageManager.php b/core/modules/language/src/ConfigurableLanguageManager.php
index d6d5075..534f232 100644
--- a/core/modules/language/src/ConfigurableLanguageManager.php
+++ b/core/modules/language/src/ConfigurableLanguageManager.php
@@ -77,7 +77,7 @@ class ConfigurableLanguageManager extends LanguageManager implements Configurabl
   /**
    * An array of language objects keyed by language type.
    *
-   * @var array
+   * @var \Drupal\Core\Language\LanguageInterface[]
    */
   protected $negotiatedLanguages;
 
diff --git a/core/modules/language/src/LanguageNegotiator.php b/core/modules/language/src/LanguageNegotiator.php
index 983b5d3..57f8490 100644
--- a/core/modules/language/src/LanguageNegotiator.php
+++ b/core/modules/language/src/LanguageNegotiator.php
@@ -71,7 +71,7 @@ class LanguageNegotiator implements LanguageNegotiatorInterface {
   /**
    * An array of language objects keyed by method id.
    *
-   * @var array
+   * @var \Drupal\Core\Language\LanguageInterface[]
    */
   protected $negotiatedLanguages = array();
 
diff --git a/core/modules/language/src/Tests/LanguageUrlRewritingTest.php b/core/modules/language/src/Tests/LanguageUrlRewritingTest.php
index 434f864..34d83ae 100644
--- a/core/modules/language/src/Tests/LanguageUrlRewritingTest.php
+++ b/core/modules/language/src/Tests/LanguageUrlRewritingTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\language\Tests;
 
 use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationUrl;
 use Drupal\simpletest\WebTestBase;
 use Symfony\Component\HttpFoundation\Request;
@@ -74,7 +75,7 @@ function testUrlRewritingEdgeCases() {
    * @param string $message2
    *   The message to display confirming prefixed URL is not working.
    */
-  private function checkUrl($language, $message1, $message2) {
+  private function checkUrl(LanguageInterface $language, $message1, $message2) {
     $options = array('language' => $language, 'script' => '');
     $base_path = trim(base_path(), '/');
     $rewritten_path = trim(str_replace($base_path, '', \Drupal::url('<front>', array(), $options)), '/');
diff --git a/core/modules/node/src/NodeStorage.php b/core/modules/node/src/NodeStorage.php
index f3c97e4..e3c90fb 100644
--- a/core/modules/node/src/NodeStorage.php
+++ b/core/modules/node/src/NodeStorage.php
@@ -52,7 +52,7 @@ public function updateType($old_type, $new_type) {
   /**
    * {@inheritdoc}
    */
-  public function clearRevisionsLanguage($language) {
+  public function clearRevisionsLanguage(LanguageInterface $language) {
     return $this->database->update('node_revision')
       ->fields(array('langcode' => LanguageInterface::LANGCODE_NOT_SPECIFIED))
       ->condition('langcode', $language->getId())
diff --git a/core/modules/node/src/NodeStorageInterface.php b/core/modules/node/src/NodeStorageInterface.php
index 1b8da20..2b5e91f 100644
--- a/core/modules/node/src/NodeStorageInterface.php
+++ b/core/modules/node/src/NodeStorageInterface.php
@@ -8,6 +8,7 @@
 namespace Drupal\node;
 
 use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Session\AccountInterface;
 
 /**
@@ -53,8 +54,8 @@ public function updateType($old_type, $new_type);
   /**
    * Unsets the language for all nodes with the given language.
    *
-   * @param $language
+   * @param \Drupal\Core\Language\LanguageInterface $language
    *  The language object.
    */
-  public function clearRevisionsLanguage($language);
+  public function clearRevisionsLanguage(LanguageInterface $language);
 }