Currency substitution (CS) and financial adaptation are in general believed to increase the equilibrium rate of inflation. This result derives from a setup in which the government finances a certain amount of real resources through money printing and where CS reduces the base of the inflation tax. This paper shows this intuition wrong for those situations where the hyperinflation is expectations-driven. Incorporating CS in an Obstfeld-Rogoff (1983) framework I show reduces the inflation rates along the hyperinflationary equilibrium. The intuition is simple: if agents have an easy way of substituting away from domestic currency then the required inflation rates to sustain a path where real balances disappears is necessarily lower. The implications of the model are then tested empirically.