diff --git a/core/modules/history/tests/src/Functional/HistoryTest.php b/core/modules/history/tests/src/Functional/HistoryTest.php
index fe07495..6b4708b 100644
--- a/core/modules/history/tests/src/Functional/HistoryTest.php
+++ b/core/modules/history/tests/src/Functional/HistoryTest.php
@@ -39,7 +39,7 @@ class HistoryTest extends BrowserTestBase {
   protected $testNode;
 
   /**
-   * The Guzzle HTTP client.
+   * The cookie jar holding the testing session cookies for Guzzle requests.
    *
    * @var \GuzzleHttp\Client;
    */
@@ -160,6 +160,7 @@ public function testHistory() {
    * Obtain the HTTP client and set the cookies.
    *
    * @return \GuzzleHttp\Client
+   *   The client with BrowserTestBase configuration.
    */
   protected function getHttpClient() {
     // Similar code is also employed to test CSRF tokens.