diff --git a/core/lib/Drupal/Core/Test/TestKernel.php b/core/lib/Drupal/Core/Test/TestKernel.php
index 6e1aa89..55909a0 100644
--- a/core/lib/Drupal/Core/Test/TestKernel.php
+++ b/core/lib/Drupal/Core/Test/TestKernel.php
@@ -24,11 +24,9 @@ class TestKernel extends DrupalKernel {
    *   The classloader.
    */
   public function __construct(ClassLoader $class_loader) {
-    $this->environment = 'test-runner';
-    $this->booted = FALSE;
-    $this->classLoader = $class_loader;
-    $this->allowDumping = FALSE;
+    parent::__construct('test_runner', $class_loader, FALSE);
 
+    // Prime the module list and corresponding Extension objects.
     // @todo Remove System module. Needed because \Drupal\Core\Datetime\Date
     //   has a (needless) dependency on the 'date_format' entity, so calls to
     //   format_date()/format_interval() cause a plugin not found exception.
@@ -47,6 +45,8 @@ public function __construct(ClassLoader $class_loader) {
    */
   public function discoverServiceProviders() {
     $providers = parent::discoverServiceProviders();
+    // The test runner does not require an installed Drupal site to exist.
+    // Therefore, its environment is identical to that of the early installer.
     $this->serviceProviderClasses[] = 'Drupal\Core\Installer\InstallerServiceProvider';
     $providers[] = new InstallerServiceProvider();
     return $providers;