How to fake delegates with FakeItEasy

When i try to fake a delegate-type, i get System.InvalidCastException

[TestMethod]
public void TestDelegateFake()
{
    var func = A.Fake<Func<long, object>>();

    A.CallTo(() => func(A<long>.Ignored))
        .Returns(new {});

    func(123);
}

How du i fake delegates?