The phenomenon of secret (siri) Muslim marriages - marriages that are conducted without state recognition - has become a hotly debated topic in Indonesia, particularly since the emergence of Muslim marriage agencies that organize unregistered online marriages. The issue is particularly contested between the state, women's activists, legal activists, and religious leaders. This article analyses the current efforts of the Indonesian state to bureaucratize Muslim marriages by insisting that unregistered marriages need to be registered with the state, and the societal responses to such regulations. Those who believe in the importance of state registration of Muslim marriage emphasize that it is an integral part of social reform. However, it has also been seen as creating problems when it only serves the interests of the majority and stands in the way of minority religious understandings, particularly by some conservative Muslims who believe that marriages within the Muslim community should be regulated by Muslim leaders ('ulam?') only, and not the state. This article argues that unregistered marriage has been the real test of the bureaucratization of religion in Indonesia. The government's effort to demonstrate its Islamic credentials by accommodating the people's majority religion has led it to assume an ambiguous position on the issue of unregistered marriages.