Syntax error: "(" unexpected

With a simple package.json
```
"scripts": {
    "delay": "npm-delay 1000"
}
```
Running `npm run delay` throws the following error:
```
/node_modules/.bin/npm-delay: 1: Syntax error: "(" unexpected
```

It works fine with
```
"scripts": {
    "delay": "node ./node_modules/npm-delay 1000"
}
```