diff --git a/core/lib/Drupal/Core/Config/ConfigBase.php b/core/lib/Drupal/Core/Config/ConfigBase.php
index 899d0de..f259dc7 100644
--- a/core/lib/Drupal/Core/Config/ConfigBase.php
+++ b/core/lib/Drupal/Core/Config/ConfigBase.php
@@ -158,9 +158,9 @@ public function get($key = '') {
    * @param array $data
    *   The new configuration data.
    * @param bool $validate_keys
-   *   Whether the data should be verified for valid keys. Set to FALSE if the
-   *   $data is known to be valid already (for example, being loaded from
-   *   the config storage).
+   *   (optional) Whether the data should be verified for valid keys. Set to
+   *   FALSE if the $data is known to be valid already (for example, being
+   *   loaded from the config storage).
    *
    * @return $this
    *   The configuration object.