Node express web server cannot load file on subdirectory

Hi I've the following code and it will load the index.html if I go to domain.com/members/ but if I go to domain.com/members then it doesn't work. How can I get around this?

  var express = require('express');
  var app = express();
  var http = require('http');
  var httpServer = http.Server(app);

  app.use( express.static(  __dirname ) );

  app.listen(3000);