node mocha async hooks not working?

Ok so I'm obviously new to mocha. From my understanding after reading the docs and googling this should work but it isn't:

describe("Check before", function(){

    var beforeCalled = false;
    before(function(){
        setTimeout(function() {
            beforeCalled = true;
            done();
        }, 150);
    });

    it("should run after before called", function(){
        expect(beforeCalled).to.equal(true);
    })
})

the it part doesn't wait for 'before' to finish and is called. Maybe I read the docs wrong or I'm missing something, not sure.

Any insight would be helpful.