Flow fails to parse a valid package.json file

My project has a dependency on https://github.com/creationix/http-parser-js/blob/master/package.json. Flow throws this error:

`
Error: node_modules/http-parser-js/package.json:1
1: {
^ Unexpected end of input
`

It looks like it's because these two lines here: https://github.com/creationix/http-parser-js/blob/master/package.json#L21-L22 contain ä and ü. But this should be valid json?