core/lib/Drupal/Core/Render/MainContent/SmartCacheHtmlRenderer.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/lib/Drupal/Core/Render/MainContent/SmartCacheHtmlRenderer.php b/core/lib/Drupal/Core/Render/MainContent/SmartCacheHtmlRenderer.php
index 7b7ca80..4839a59 100644
--- a/core/lib/Drupal/Core/Render/MainContent/SmartCacheHtmlRenderer.php
+++ b/core/lib/Drupal/Core/Render/MainContent/SmartCacheHtmlRenderer.php
@@ -132,7 +132,7 @@ protected function finish(array $html) {
     $html_cache_max_age = Cache::PERMANENT;
     // SmartCache always caches per route, so always include that cache context.
     $html_cache_contexts = ['route'];
-    $html_cache_tags = [];
+    $html_cache_tags = ['rendered'];
     foreach (Element::children($cacheable_html) as $child) {
       $cacheable_html[$child] = $this->renderCache->getCacheableRenderArray($cacheable_html[$child]);
       $html_cache_contexts = Cache::mergeContexts($html_cache_contexts, $cacheable_html[$child]['#cache']['contexts']);