Object.freeze pattern legal in 2.3, rejected in 2.4

[evmar]

TypeScript Version: 2.4.2

Code

Object.freeze({
  foo() {
    return Object.freeze('a');
  },
});

(with --strict)

Expected behavior:
Accepted in 2.3 and 2.4.

Actual behavior:
In 2.4: 'foo' implicitly has return type 'any' because it does not have a return type annotation and is referenced directly or indirectly in one of its return expressions.

Note that the TS playground currently is 2.3.3, so you can't reproduce this on there.