core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php                | 2 +-
 .../tests/modules/twig_theme_test/src/TwigThemeTestController.php       | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php b/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php
index d9d0858..fca409d 100644
--- a/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php
+++ b/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php
@@ -150,7 +150,7 @@ public function renderResponse(array $main_content, Request $request, RouteMatch
     // Merge the request's access result cacheability metadata, if it has any.
     $access_result = $request->attributes->get(AccessAwareRouterInterface::ACCESS_RESULT);
     if ($access_result instanceof CacheableInterface) {
-      $cache_contexts = Cache::mergeTags($cache_tags, $access_result->getCacheContexts());
+      $cache_contexts = Cache::mergeContexts($cache_contexts, $access_result->getCacheContexts());
       $cache_tags = Cache::mergeTags($cache_tags, $access_result->getCacheTags());
     }
 
diff --git a/core/modules/system/tests/modules/twig_theme_test/src/TwigThemeTestController.php b/core/modules/system/tests/modules/twig_theme_test/src/TwigThemeTestController.php
index ff49bd6..e935afb 100644
--- a/core/modules/system/tests/modules/twig_theme_test/src/TwigThemeTestController.php
+++ b/core/modules/system/tests/modules/twig_theme_test/src/TwigThemeTestController.php
@@ -72,6 +72,7 @@ public function fileUrlRender() {
    * Menu callback for testing the Twig registry loader.
    */
   public function registryLoaderRender() {
+    \Drupal::service('page_cache_kill_switch')->trigger();
     return array('#theme' => 'twig_registry_loader_test');
   }