diff --git a/core/tests/Drupal/Tests/BrowserTestBase.php b/core/tests/Drupal/Tests/BrowserTestBase.php
index 47878ad..b4a685e 100644
--- a/core/tests/Drupal/Tests/BrowserTestBase.php
+++ b/core/tests/Drupal/Tests/BrowserTestBase.php
@@ -1615,18 +1615,14 @@ protected function cssSelect($selector) {
    *
    * @param string|\Drupal\Component\Render\MarkupInterface $label
    *   Text between the anchor tags.
-   * @param int|null $index
-   *   (optional) The index number for cases where multiple links have the text.
+   * @param int $index
+   *   (optional) The index number for cases where multiple links have the same
+   *   text. Defaults to 0.
    */
-  protected function clickLink($label, $index = NULL) {
+  protected function clickLink($label, $index = 0) {
     $label = (string) $label;
-    if (is_integer($index)) {
-      $links = $this->getSession()->getPage()->findAll('named', array('link', $label));
-      $links[$index]->click();
-    }
-    else {
-      $this->getSession()->getPage()->clickLink($label);
-    }
+    $links = $this->getSession()->getPage()->findAll('named', ['link', $label]);
+    $links[$index]->click();
   }
 
   /**