This paper addresses how the Ottoman state, at a critical moment, used fatwas to negotiate its way between the Islamic legal tradition, agreements with other powers, and the needs of a bureaucratized state apparatus. I do this by exploring the debates around the release of enslaved children after the Ottoman-Russian Treaty of Küçük Kaynarca (1774), and the Ottoman-Austrian Treaty of Sistova (1791). Both agreements required that captives be returned, but converts to the captor state’s religion were exempted. This raised a vital question: at what age were children competent to convert? In the 1770s, the Ottomans defensively asserted a reified, arguably “self-Orientalized” view of the legal importance of childhood conversions in order to oppose Russian claims and save face politically. But faced with Russian threats, they eventually agreed that children above a certain age were to be allowed to convert, while those below that age were not. Crucially, this was a considerable simplification of Islamic legal traditions, which valued mental competence above abstract age-based tests—but it was well-adapted to bureaucratic implementation. Similar questions arose following the Treaty of Sistova, and in the main portion of the paper, I conduct a detailed analysis of three fatwas preserved in the Ottoman archives from this period. Requested by the Porte from the chief jurisconsult (?eyhülislam), these clarify the status of child converts under Islamic law, but in a curious way. I place the fatwas' legal reasoning in the context of Hanafi legal tradition, showing crucial discontinuities. These discontinuities reveal legal sleight-of-hand, as the state attempted to imply justification for a conversion test which was not really valid. Yet, I argue, the fatwas reveal neither a blind adherence to tradition nor an abject concession to outside pressure, but a good-faith effort to reconcile international treaty obligations with domestic legal commitments and the bureaucratic need for a simple, legible conversion test. This was hardly a uniquely Ottoman question. Eighteenth-century European theorists argued that treaty law could never trump “natural law,” just as the US Supreme Court, in the past decade, has taken up the question of whether, and when, treaties can outweigh American domestic law. Thus, I close by suggesting that the Ottoman experience of international law was not an exceptional one of encounter and submission, but had much in common with that of its contemporaries, and of other states which see themselves as legally exceptional—including as the world’s current leading power.