diff --git a/README.rdoc b/README.rdoc
index 3fc30272e2..f27d2ceed4 100644
--- a/README.rdoc
+++ b/README.rdoc
@@ -1523,6 +1523,7 @@ assign them to a constant, you can do this with <tt>Sinatra.new</tt>:
 
 It takes the application to inherit from as optional argument:
 
+  # config.ru
   require 'sinatra/base'
 
   controller = Sinatra.new do