  Starting from an effective action for quantum gravity, we calculate the
quantum gravitational corrections to the Wald entropy of a four dimensional
non-extremal Reissner-Nordstr\"om (RN) black hole in the limit of small
electric charge, generalising a previous calculation carried out by Calmet and
Kuipers [1] for a Schwarzschild black hole. We show that, at second order in
the Ricci curvature, the RN metric receives quantum corrections which shift the
classical position of the event horizon. We apply the Wald entropy formula by
integrating over the perimeter of the quantum corrected event horizon. We then
compute the quantum gravitational corrections to the temperature and the
pressure of the black hole.
