diff --git a/core/lib/Drupal/Core/Render/Renderer.php b/core/lib/Drupal/Core/Render/Renderer.php
index b1f7c2a..38d8445 100644
--- a/core/lib/Drupal/Core/Render/Renderer.php
+++ b/core/lib/Drupal/Core/Render/Renderer.php
@@ -530,7 +530,12 @@ protected function doRender(&$elements, $is_root_call = FALSE) {
     $prefix = isset($elements['#prefix']) ? $this->xssFilterAdminIfUnsafe($elements['#prefix']) : '';
     $suffix = isset($elements['#suffix']) ? $this->xssFilterAdminIfUnsafe($elements['#suffix']) : '';
 
-    $elements['#markup'] = Markup::create($prefix . $elements['#children'] . $suffix);
+    if (isset($elements['#render_children'])) {
+      $elements['#markup'] = Markup::create($elements['#children']);
+    }
+    else {
+      $elements['#markup'] = Markup::create($prefix . $elements['#children'] . $suffix);
+    }
 
     // We've rendered this element (and its subtree!), now update the context.
     $context->update($elements);