What is the ruling on make-up for days of Ramadan fasted by a child before maturity, or before Islam?

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For the remainder of the month after maturity, there is no difference of opinion regarding the continuation of the fast. Regarding the make-up for days of the month preceding conversion to Islam, it is not obligatory. This view is held by al-Sha'bi, Qatadah, Malik, al-Awza'i, al-Shafi'i, Abu Thawr, and the proponents of the opinion of Abu Hanifa. The justification is that the past act was worship performed during a state of disbelief, so its make-up is not required, similar to a past Ramadan.