diff --git a/config.ru b/config.ru
index ad1fbf29..949a0571 100644
--- a/config.ru
+++ b/config.ru
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 # This file is used by Rack-based servers to start the application.
 
 require_relative 'config/environment'
 
 run Rails.application
-Rails.application.load_server
+Rails.application.load_server if Rails::VERSION::MAJOR == 6