NPM shrinkwrap packages everything under node_modules regardless

[jdkb123]

I have package.json that has devdependancies and dependencies listed. I then did npm install and that installed all the packages locally under node_modules folder. Now when I run npm shrinkwrap, I expected the npm-shrinkwrap.json to contain only the dependencies and their chain. Instead I see that it just simply went thru node_modules and just everything there in npm-shrinkwrap.json.