diff --git a/core/lib/Drupal/Core/EventSubscriber/SpecialAttributesRouteSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/SpecialAttributesRouteSubscriber.php
index 22e82d2..c2bb9df 100644
--- a/core/lib/Drupal/Core/EventSubscriber/SpecialAttributesRouteSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/SpecialAttributesRouteSubscriber.php
@@ -44,9 +44,7 @@ public function onRouteBuilding(RouteBuildEvent $event) {
     foreach ($event->getRouteCollection()->all() as $route) {
       if ($not_allowed_variables = array_intersect($route->compile()->getVariables(), $special_variables)) {
         $placeholders = array('@variables' => implode(', ', $not_allowed_variables));
-        drupal_set_message(String::format('The following variables are reserved names by drupal: @variables', $placeholders));
-        watchdog('error', 'The following variables are reserved names by drupal: @variables', $placeholders);
-        return FALSE;
+        throw new \InvalidArgumentException(String::format('The following variables are reserved names by drupal: @variables', $placeholders));
       }
     }
     return TRUE;
diff --git a/core/tests/Drupal/Tests/Core/EventSubscriber/SpecialAttributesRouteSubscriberTest.php b/core/tests/Drupal/Tests/Core/EventSubscriber/SpecialAttributesRouteSubscriberTest.php
index 7555768..317bf02 100644
--- a/core/tests/Drupal/Tests/Core/EventSubscriber/SpecialAttributesRouteSubscriberTest.php
+++ b/core/tests/Drupal/Tests/Core/EventSubscriber/SpecialAttributesRouteSubscriberTest.php
@@ -104,13 +104,15 @@ public function testOnRouteBuildingValidVariables(Route $route) {
    * @param \Symfony\Component\Routing\Route $route
    *   The route to check.
    *
+   * @expectedException \InvalidArgumentException
+   *
    * @dataProvider providerTestOnRouteBuildingInvalidVariables
    */
   public function testOnRouteBuildingInvalidVariables(Route $route) {
     $route_collection = new RouteCollection();
     $route_collection->add('test', $route);
     $event = new RouteBuildEvent($route_collection, 'test');
-    $this->assertFalse($this->specialAttributesRouteSubscriber->onRouteBuilding($event));
+    $this->specialAttributesRouteSubscriber->onRouteBuilding($event);
   }
 
 }