.../src/CacheabilitySafeguardsServiceProvider.php                    | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/core/modules/cacheability_safeguards/src/CacheabilitySafeguardsServiceProvider.php b/core/modules/cacheability_safeguards/src/CacheabilitySafeguardsServiceProvider.php
index 83d69be..78a8b37 100644
--- a/core/modules/cacheability_safeguards/src/CacheabilitySafeguardsServiceProvider.php
+++ b/core/modules/cacheability_safeguards/src/CacheabilitySafeguardsServiceProvider.php
@@ -20,6 +20,11 @@ class CacheabilitySafeguardsServiceProvider implements ServiceModifierInterface
    * {@inheritdoc}
    */
   public function alter(ContainerBuilder $container) {
+    // Allow sites to opt out from the cacheability safeguards.
+    if ($container->hasParameter('cacheability_safeguards') && $container->getParameter('cacheability_safeguards') === FALSE) {
+      return;
+    }
+
     // Also make the 'user.permissions' cache context required.
     if ($container->hasParameter('renderer.config')) {
       $renderer_config = $container->getParameter('renderer.config');