diff --git a/core/lib/Drupal/Core/Session/UserSession.php b/core/lib/Drupal/Core/Session/UserSession.php
index 3ed8247..05de401 100644
--- a/core/lib/Drupal/Core/Session/UserSession.php
+++ b/core/lib/Drupal/Core/Session/UserSession.php
@@ -59,7 +59,7 @@ class UserSession implements UserSessionInterface {
   public $session;
 
   /**
-   * .
+   * The Unix timestamp when this session last requested a page.
    *
    * @var string.
    */
@@ -112,4 +112,4 @@ public function getSessionId() {
     return $this->sid;
   }
 
-}
\ No newline at end of file
+}
diff --git a/core/lib/Drupal/Core/Session/UserSessionInterface.php b/core/lib/Drupal/Core/Session/UserSessionInterface.php
index 2e7cac7..b79d818 100644
--- a/core/lib/Drupal/Core/Session/UserSessionInterface.php
+++ b/core/lib/Drupal/Core/Session/UserSessionInterface.php
@@ -53,4 +53,4 @@ public function getSecureSessionId();
    *   Array with the session data that belongs to this object.
    */
   public function getSessionData();
-}
\ No newline at end of file
+}