diff --git a/core/modules/simpletest/src/JavascriptTestBase.php b/core/modules/simpletest/src/JavascriptTestBase.php
index f7cdc11..a4640bb 100644
--- a/core/modules/simpletest/src/JavascriptTestBase.php
+++ b/core/modules/simpletest/src/JavascriptTestBase.php
@@ -25,17 +25,13 @@
   /**
    * {@inheritdoc}
    */
-  protected $minkDefaultDriverArgs = [
-    'http://127.0.0.1:8510',
-    '/tmp/browsertestbase-templatecache',
-  ];
-
-  /**
-   * {@inheritdoc}
-   */
   protected function initMink() {
     // Setup some template cache using by the phantomjs mink driver.
-    $path = sys_get_temp_dir() . DIRECTORY_SEPARATOR . 'browsertestbase-templatecache';
+    $path = $this->tempFilesDirectory . DIRECTORY_SEPARATOR . 'browsertestbase-templatecache';
+    $this->minkDefaultDriverArgs = [
+      'http://127.0.0.1:8510',
+      $path,
+    ];
     if (!file_exists($path)) {
       mkdir($path);
     }