"Nested" arrow function SyntaxError on 1v90

Hi all, I'm seeing this:

var Util = {
    foo:x=>x.forEach(e=>console.log(e.length))
};

This is valid ES6 code (https://repl.it/EyUS/0), yet:

Uncaught SyntaxError: Got ID:console expected ','
 at line 3 col 23
  foo:(x)=>x.forEach(e=>console.log(e.length))
                      ^
 at line 3 col 25
  foo:(x)=>x.forEach(e=>console.log(e.length))
                        ^

Am I misunderstanding something, or is this a bug in the interpreter?