diff --git a/core/lib/Drupal/Core/EventSubscriber/AcceptNegotiation406.php b/core/lib/Drupal/Core/EventSubscriber/AcceptNegotiation406.php
new file mode 100644
index 0000000..da4fa32
--- /dev/null
+++ b/core/lib/Drupal/Core/EventSubscriber/AcceptNegotiation406.php
@@ -0,0 +1,44 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\EventSubscriber\AcceptNegotiation406.
+ */
+
+namespace Drupal\Core\EventSubscriber;
+
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent;
+use Symfony\Component\HttpKernel\Exception\NotAcceptableHttpException;
+use Symfony\Component\HttpKernel\KernelEvents;
+
+/**
+ * View subscriber rendering a 406 if we could not route or render a request.
+ *
+ * @todo fix or replace this in https://www.drupal.org/node/2364011
+ */
+class AcceptNegotiation406 implements EventSubscriberInterface {
+
+  function onViewDetect406(GetResponseForControllerResultEvent $event) {
+    $request = $event->getRequest();
+    $result = $event->getControllerResult();
+
+    // If this is a render array then we assume that the router went with the
+    // generic controller and not one with a format. If the format requested is
+    // not HTML though we can also assume that the requested format is invalid
+    // so we provide a 406 response.
+    if (is_array($result) && $request->getRequestFormat() !== 'html') {
+      throw new NotAcceptableHttpException('Not acceptable');
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  static function getSubscribedEvents() {
+    $events[KernelEvents::VIEW][] = ['onViewDetect406', -10];
+
+    return $events;
+  }
+
+}