Empty "default" in a switch causes unreachable code error

[evmar]

Using TS master from May 23:

function foo(x: any) {
  switch (x) {
    case 1: return;
    default:
  }
  console.log('x');
}

Produces an 'unreachable code' error on the console.log.
If you put anything after the 'default:', e.g. 1; then it is accepted.
I imagine the empty default case is somehow being treated as terminal.