Is expiation obligatory for one who broke an oath after apostatizing, then repenting and returning to Islam?

The jurists differed regarding the validity of an oath taken by a disbeliever or an apostate. The Hanafis and Malikis held that an oath taken by a disbeliever is not valid, and that apostasy nullifies the oath. Whereas the Shafi'is and Hanbalis held that an oath taken by a disbeliever is valid, and that Islam is not a condition for the validity or continuation of an oath. They also held that a disbeliever who is bound by the rulings – a Dhimmi (protected non-Muslim) or an apostate – is required to pay expiation if he breaks his oath while still a disbeliever, with some detailed considerations in the case of the apostate.