diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index 6127738..1ea2bc1 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -277,6 +277,7 @@ public static function config($name) {
    * or off.
    *
    * @return \Drupal\Core\Config\ConfigFactoryInterface
+   *   The configuration factory service.
    */
   public static function configFactory() {
     return static::$container->get('config.factory');
diff --git a/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php b/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php
index 1969e82..e836a2b 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php
@@ -58,7 +58,7 @@ public function get($name);
    * @param array $names
    *   List of names of configuration objects.
    *
-   * @return array
+   * @return \Drupal\Core\Config\Config[]
    *   List of successfully loaded configuration objects, keyed by name.
    */
   public function loadMultiple(array $names);
@@ -66,7 +66,7 @@ public function loadMultiple(array $names);
   /**
    * Resets and re-initializes configuration objects. Internal use only.
    *
-   * @param string $name
+   * @param string|null $name
    *   (optional) The name of the configuration object to reset. If omitted, all
    *   configuration objects are reset.
    *
@@ -119,7 +119,7 @@ public function clearStaticCache();
   /**
    * Sets the language to be used in configuration overrides.
    *
-   * @param \Drupal\Core\Language\Language $language
+   * @param \Drupal\Core\Language\Language|null $language
    *   The language object to be set on the config factory. Used to override
    *   configuration by language.
    *