Is it obligatory to make up the last two days of Sha'ban for someone who fasted them as a make-up, despite the prohibition of fasting a day or two before Ramadan, except for those accustomed to fasting on Mondays and Thursdays?

The Prophet, peace and blessings be upon him, forbade anticipating Ramadan by fasting one or two days, except for one who has a regular habit of fasting. Scholars explained the prohibition by stating that the ruling on fasting is tied to the sighting of the moon. Exempted from this are fasts for making up missed days (qada') and vows (nadhr), due to their obligatory nature. It is obligatory to make up missed days from Ramadan before the next Ramadan begins; otherwise, an expiation (kaffara) is required along with the make-up fast.