  We investigate quantum corrections to the effective action of the universal
hypermultiplet in the language of projective superspace. We rederive the
recently found one-loop correction to the universal hypermultiplet moduli space
geometry. The deformed metric is described as a superspace action in terms of a
single function, homogeneous of first degree. Our framework leads us to a
natural proposal for the nonperturbative moduli space metric induced by
five-brane instantons.
