How do i let my node-script search for modules in `{executing directory}/node_modules`?

Long story short:

I have a script in my personal bin-folder in ~/dotfiles/bin/myscript which is added to $PATH by export PATH=~/dotfiles/bin:$PATH.

The current content of myscript is

#! /usr/bin/env node

var prompt = require('prompt');

prompt is installed globally and locally. But require('prompt') says it

Cannot find module 'prompt'

I found out, that require() usually searches modules in

• ./node_modules (local)
• {prefix}/lib/node_modules (global)

I found my {prefix} by npm config get prefix.

So i could install the package in ~/dotfiles/bin/node_modules or use require('/usr/local/lib/node_modules/prompt'); in my script. Both work, but are no solution to me.

So the question is: How do i let my node-script search for modules in {executing directory}/node_modules? And why isn't require() searching in /usr/local/lib/node_modules/ anyway?