O–C diagrams (upper panels) and optical and X-ray light curves (bottom panels, arbitrary scaling to emphasise the change in flux) of SSS J122222 (left-hand panel) and GW Lib (right-hand panel). The O–C diagram of SSS J122222 is taken from Paper I. To create the O–C diagram of GW Lib, we used the timings of superhump maxima from Table 152 in Kato et al. (2009). The stages of the superhump evolution are marked following Kato et al. (2013) and Kato et al. (2009).