Here we present the asteroseismic results for HD 212771, an ascending red giant branch star, known to be an exoplanet host. The star was observed in Campaign 3 of the K2 Mission, allowing for a detailed asteroseismic analysis of the star. The higher accuracy and precision of asteroseismology provides a mass for HD 212771 consistent with the star having been a G type dwarf during its main sequence lifetime, whilst literature values indicate an F or A type star, with literature masses derived from the fitting of spectroscopic parameters to isochrones. The lower mass from asteroseismology may provide a solution to the observed difference in mass distribution of exoplanet hosts between dwarf and evolved hosts, with the masses derived from isochrone fitting being overestimated, whilst asteroseismology recovers the true mass.