diff --git a/core/themes/engines/twig/twig.engine b/core/themes/engines/twig/twig.engine
index 370b56c..bc7e75d 100644
--- a/core/themes/engines/twig/twig.engine
+++ b/core/themes/engines/twig/twig.engine
@@ -115,6 +115,11 @@ function twig_render_var($arg) {
     return $arg;
   }
 
+  // Treat output from RenderWrapper as safe, return a Twig_Markup instance.
+  if ($arg instanceof \Drupal\Core\Template\RenderWrapper) {
+    return new Twig_Markup((string) $arg, 'UTF-8');
+  }
+
   if (is_scalar($arg)) {
     if (isset($GLOBALS['safe_strings'][$arg])) {
       return new Twig_Markup($arg, 'UTF-8');