Some Russian last names end in -ович. That's right: every once in a while you come across a last name that looks like an отчество patronymic. For such names the general rule is that if the bearer is a man, the last name declines, but if the bearer is a woman, the last name doesn't decline. One person who has such a last name is the well-known composer Дмитрий Шостакович. His own name declines like this:

His wife's name declines like this: