npm-check-updates TypeError

So I've updated my Node version to v8 as of this morning, and had to update a couple node_modules.

Also installed npm-check-updates to update the package.json file with the latest versions that were installed but it's throwing the following error. Was wondering if anyone knew why this is happening / how to solve?

pi@raspberryPi:/var/node $ npm-check-updates -u
[INFO]: You can also use ncu as an alias
/home/pi/.nvm/versions/node/v8.0.0/lib/node_modules/npm-check-updates/node_modules/require-dir/index.js:97
            if (!require.extensions.hasOwnProperty(ext)) {
                                    ^

TypeError: require.extensions.hasOwnProperty is not a function
    at requireDir (/home/pi/.nvm/versions/node/v8.0.0/lib/node_modules/npm-check-updates/node_modules/require-dir/index.js:97:37)
    at Object.<anonymous> (/home/pi/.nvm/versions/node/v8.0.0/lib/node_modules/npm-check-updates/lib/versionmanager.js:8:23)
    at Module._compile (module.js:569:30)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:503:32)
    at tryModuleLoad (module.js:466:12)
    at Function.Module._load (module.js:458:3)
    at Module.require (module.js:513:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (/home/pi/.nvm/versions/node/v8.0.0/lib/node_modules/npm-check-updates/lib/npm-check-updates.js:14:10)
    at Module._compile (module.js:569:30)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:503:32)
    at tryModuleLoad (module.js:466:12)
    at Function.Module._load (module.js:458:3)
    at Module.require (module.js:513:17)
pi@raspberryPi:/var/node $

via Josh Scott