Cumulative PNLFs for the LMC PN sample from Reid & Parker (2010) shifted to the apparent bright cut-off of the M 31 disc region at 10 < R_GC ≤ 20 kpc. The cumulative PNLFs are fitted by the generalised cumulative function (in blue) for m₅₀₀₇ ≤ 24.5 mag and a function which additionally includes an exponential at the faint end (in orange). The uncertainties of the fits are shaded. The region fainter than the limiting magnitude of the shallowest field (m₅₀₀₇ > 26.16 mag) in our M 31 survey is shown in grey.