diff --git a/core/lib/Drupal/Core/Test/TestRunnerKernel.php b/core/lib/Drupal/Core/Test/TestRunnerKernel.php
index 9d22b6d..e78cc5f 100644
--- a/core/lib/Drupal/Core/Test/TestRunnerKernel.php
+++ b/core/lib/Drupal/Core/Test/TestRunnerKernel.php
@@ -9,7 +9,6 @@
 
 use Drupal\Core\DrupalKernel;
 use Drupal\Core\Extension\Extension;
-use Drupal\Core\SAPI\NullSAPIAdapter;
 use Drupal\Core\Site\Settings;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -22,9 +21,6 @@ class TestRunnerKernel extends DrupalKernel {
    * {@inheritdoc}
    */
   public static function createFromRequest(Request $request, $class_loader, $environment = 'test_runner', $allow_dumping = TRUE, $sapi_adapter = NULL) {
-    if (!isset($sapi_adapter)) {
-      $sapi_adapter = new NullSAPIAdapter();
-    }
     return parent::createFromRequest($request, $class_loader, $environment, $allow_dumping, $sapi_adapter);
   }
 
diff --git a/core/modules/simpletest/src/BrowserTestBase.php b/core/modules/simpletest/src/BrowserTestBase.php
index 70cda3e..944722b 100644
--- a/core/modules/simpletest/src/BrowserTestBase.php
+++ b/core/modules/simpletest/src/BrowserTestBase.php
@@ -60,6 +60,13 @@
   protected $classLoader;
 
   /**
+   * The SAPI adapter.
+   *
+   * @var \Drupal\Core\SAPI\SAPIAdapterInterface.
+   */
+  protected $sapiAdapter;
+
+  /**
    * The site directory of this test run.
    *
    * @var string
@@ -889,8 +896,7 @@ public function installDrupal() {
     chmod($directory, 0777);
 
     $request = \Drupal::request();
-    $sapi_adapter = new NullSAPIAdapter();
-    $this->kernel = DrupalKernel::createFromRequest($request, $this->classLoader, 'prod', TRUE, $sapi_adapter);
+    $this->kernel = DrupalKernel::createFromRequest($request, $this->classLoader, 'prod', TRUE, $this->sapiAdapter);
     $this->kernel->prepareLegacyRequest($request);
     // Force the container to be built from scratch instead of loaded from the
     // disk. This forces us to not accidentally load the parent site.
@@ -1082,8 +1088,9 @@ private function changeDatabasePrefix() {
   protected function prepareEnvironment() {
     // Bootstrap Drupal so we can use Drupal's built in functions.
     $this->classLoader = require __DIR__ . '/../../../../autoload.php';
+    $this->sapiAdapter = NullSAPIAdapter();
     $request = Request::createFromGlobals();
-    $kernel = TestRunnerKernel::createFromRequest($request, $this->classLoader);
+    $kernel = TestRunnerKernel::createFromRequest($request, $this->classLoader, 'test_runner', FALSE, $this->sapiAdapter);
     // TestRunnerKernel expects the working directory to be DRUPAL_ROOT.
     chdir(DRUPAL_ROOT);
     $kernel->prepareLegacyRequest($request);