Empirical relation of WLF energy and GOES flux for solar flares and power-law fits performed by Namekata et al. (2017) on them using a linear regression method and a linear regression bisector method (solid and dashed lines). The red line is our fit including the AD Leo superflare, which yields in the double logarithmic form (log E_WLF = a + b ⋅ log F_GOES), a slope b = 1.150 ± 0.005, and an axis-offset of a = 34.711 ± 0.007, where the uncertainties are the standard deviations of the fit.