Large black holes in an asymptotically Anti-de Sitter spacetime have a dual description in terms of approximately thermal states in the boundary CFT. The reflecting boundary conditions of AdS prevent such black holes from evaporating completely. However, this situation is not ideal for the formulation of the black hole information paradox, which requires the ability of the black hole to evaporate. This can be accomplished by making the boundary of AdS partially absorptive, corresponding to a particular deformation of the gauge theory in view of the AdS/CFT correspondence. I will discuss a simple construction that produces the necessary changes on the boundary conditions. The model couples a scalar field in $1+1$ dimensions to a scalar field on AdS. The interaction is localized at the boundary and leads to partial transmission into the auxiliary space. Evaporation of the large black hole corresponds to cooling down the CFT by transferring energy to an external sector.