The problem with this reply is that it involves the mathematical fictionalist program in a circle. The fictionalist cannot rely on the conservativeness of mathematics to justify the use of a mathematical result (the compactness theorem) that is required for the formulation of the notion of conservativeness itself. For in doing that, the fictionalist assumes that the notion of conservativeness is nominalistically acceptable, and this is exactly the point in question. Recall that the motivation for Field to use the compactness theorem was to reformulate conservativeness without having to assume abstract entities (namely, those required by the semantic and the proof-theoretic accounts of consistency). Thus, at this point, the mathematical fictionalist cannot yet use the notion of conservativeness; otherwise, the whole program would not get off the ground. I conclude that, similarly to any other part of mathematics, metalogical results also need to be obtained nominalistically. Trouble arises for nominalism otherwise.