diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 21abf8b..94b7b84 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -440,6 +440,10 @@ function install_begin_request($class_loader, &$install_state) {
 
   // Load all modules and perform request related initialization.
   $kernel->preHandle($request);
+
+  // Initialize a route on this legacy request similar to
+  // \Drupal\Core\DrupalKernel::prepareLegacyRequest() since normal routing
+  // will not happen.
   $request->attributes->set(RouteObjectInterface::ROUTE_OBJECT, new Route('<none>'));
   $request->attributes->set(RouteObjectInterface::ROUTE_NAME, '<none>');