Belgium is one of the first European countries where the public authority in charge for asylum, the Office of the Commissioner General for Refugees and Stateless Persons (CGRS), has provided for its protection officers specific instruments to process sexual orientation-based asylum cases. This paper argues that the three different stages of development of these instruments within the CGRS (emergence between 2000 and 2004, stabilisation between 2005 and 2009, lock-in since 2010), as a result of their materiality and own rationality, have led to a de facto acknowledgment of a “new” ground to grant refugee status. By opening the “black box” of the asylum administration, this analysis makes it possible to go beyond arguments in terms of Europeanisation, instruments diffusion, cultural and social evolutions, and political voluntarism proposed in the scientific literature to justify broadening the definition of the refugee to the people persecuted based on their sexual orientation.