No way to type an object with null prototype

Currently the base type of all objects in TS seems to be {}, which looks like an empty type but actually has members inherited from the Object object. This leaves no way to express a type with null prototype.

var foo: ??? = Object.create(null);
foo.toString(); // Want a compile error here

I did accidentally discover that it's possible to type a variable as void:

var foo: void = Object.create(null);

This appears to suppress intellisense for members in VS and the playground, and it is assignable to any (Object.keys(foo) compiles), so it would seem to be what I'm looking for. However this still lets foo.toString() compile somehow - I imagine the void type is getting elevated to Object automatically.

Edit: Ryan's workaround to subtype Object and override all its members to void prevents those properties from being called as functions, but as he points out, that doesn't prevent them from being accessed.

var bar = foo.toString; // Want a compiler error here too. Won't get one with Ryan's workaround.

Reproduce the Object.create(null) examples in the TypeScript playground, then trace how {}, void, and Object members are modeled. Done means a supported type can represent a null-prototype object and rejects both member-access examples. The issue does not name a file or test to target.