diff --git a/core/lib/Drupal/Core/Form/FormState.php b/core/lib/Drupal/Core/Form/FormState.php
index 9d651cd..0ea08a5 100644
--- a/core/lib/Drupal/Core/Form/FormState.php
+++ b/core/lib/Drupal/Core/Form/FormState.php
@@ -1008,6 +1008,9 @@ public function getResponse() {
    * {@inheritdoc}
    */
   public function setRedirect($route_name, array $route_parameters = array(), array $options = array()) {
+    if (!\Drupal::accessManager()->checkNamedRoute($route_name, $route_parameters)) {
+      throw new \Exception('boo');
+    }
     $url = new Url($route_name, $route_parameters, $options);
     return $this->setRedirectUrl($url);
   }
diff --git a/core/modules/simpletest/src/BrowserTestBase.php b/core/modules/simpletest/src/BrowserTestBase.php
index e531b65..7565d33 100644
--- a/core/modules/simpletest/src/BrowserTestBase.php
+++ b/core/modules/simpletest/src/BrowserTestBase.php
@@ -31,6 +31,10 @@
 /**
  * Test case for functional Drupal tests.
  *
+ * Currently this class should only be used for JavaScript testing, for
+ * everything else, WebTestBase is better for now. This is likely to change
+ * after Drupal 8.0
+ *
  * @ingroup testing
  *
  * All BrowserTestBase tests must have two annotations to ensure process