diff --git a/docs/guide/structure.rst b/docs/guide/structure.rst
index 8e8dc026a3..34a37ebd56 100644
--- a/docs/guide/structure.rst
+++ b/docs/guide/structure.rst
@@ -59,6 +59,8 @@ are mapped to ``StoryHandler``.  That number is passed (as a string) to
 ``StoryHandler.get``.
 
 ::
+import tornado.ioloop
+from tornado.web import Application, RequestHandler, url
 
     class MainHandler(RequestHandler):
         def get(self):
@@ -77,6 +79,10 @@ are mapped to ``StoryHandler``.  That number is passed (as a string) to
         url(r"/story/([0-9]+)", StoryHandler, dict(db=db), name="story")
         ])
 
+if __name__ == "__main__":
+    app.listen(8888)
+    tornado.ioloop.IOLoop.current().start()
+
 The `.Application` constructor takes many keyword arguments that
 can be used to customize the behavior of the application and enable
 optional features; see `.Application.settings` for the complete list.