The package webpack@2.1.0-beta.5 does not satisfy its siblings'

Getting the same problem on Pi using 3.1 ( 9742382 ) (only it's webpack@2.1.0-beta.7)

npm ERR! code EPEERINVALID

npm ERR! peerinvalid The package webpack@2.1.0-beta.7 does not satisfy its siblings' peerDependencies requirements!
npm ERR! peerinvalid Peer mocha-webpack@0.3.0 wants webpack@^1.12.13
npm ERR! peerinvalid Peer sass-loader@3.2.0 wants webpack@^1.12.6
npm ERR! peerinvalid Peer extract-text-webpack-plugin@1.0.1 wants webpack@^1.9.11
npm ERR! peerinvalid Peer babel-loader@6.2.4 wants webpack@1 || ^2.1.0-beta

Have edited webapp/package.json up to webpack 2.1.0-beta.13 and my build is running a lot longer. But it's on a Pi2... so it's taking it's time.