Nonequilibrium simulation methods and rigid-body path-integral techniques are combined to estimate the relevance of protonic quantum effects in the free energy of ion water clusters. The Crooks' fluctuation relation is used to quantitatively characterize the impact of quantum effects on the dissociation free energy of the paradigm I-(H2O)(5). By use of a rigorous smoothing procedure in the calculation of the work distributions, the effects are found to be about 11% and therefore non-negligible. Quantum effects on the potential of mean force of Na+(H2O)(12) were also evaluated using Jarzynski's work theorem for a reaction coordinate, and they were also found to be significant. The results suggest that quantization should play a significant role in the kinetics of ionic transport in aqueous environments.