express.js - devDependencies imports in production installations

I am developing an express.js application. In the server.js file I have development env specific code which uses devDependencies imports:

// server.js
import webpack from 'webpack'; // devDependency 
import webpackMiddleware from 'webpack-dev-middleware'; // devDependency 
...
if (app.settings.env === 'development') {
  app.use(webpackMiddleware(webpack(config));
}
...

When I deploy my application to production, I will not install devDependencies and the code will not run because these packages will not be installed.

What is the best practice for this situation?

via David Tzoor