diff --git a/core/modules/simpletest/src/BrowserTestBase.php b/core/modules/simpletest/src/BrowserTestBase.php
index f3c01f7..049db12 100644
--- a/core/modules/simpletest/src/BrowserTestBase.php
+++ b/core/modules/simpletest/src/BrowserTestBase.php
@@ -235,6 +235,9 @@
 
   /**
    * Initializes Mink sessions.
+   *
+   * @return \Behat\Mink\Session
+   *   The mink session.
    */
   protected function initMink() {
     $driver = $this->getDefaultDriverInstance();
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/JavascriptTestBase.php b/core/tests/Drupal/FunctionalJavascriptTests/JavascriptTestBase.php
index 65927a0..85afeab 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/JavascriptTestBase.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/JavascriptTestBase.php
@@ -36,7 +36,7 @@ protected function initMink() {
     if (!file_exists($path)) {
       mkdir($path);
     }
-    parent::initMink();
+    return parent::initMink();
   }
 
   /**