Though the job of breastfeeding is typically known to the women, there are documented cases of men producing breast milk. However, these reports are few and far between, which means that while men do have the ability to produce milk, it doesn't happen often.
Let's say that in an alternate universe, male lactation is as routine as female lactation without the use of fertility drugs or breast pumps. Would this require a change in male anatomy? If yes, how?