Upper panel: entire light curve of CoRoT 223959652 (open diamonds) together with the best fits obtained by fitting individual intervals of the same length as that used to search for differential rotation (indicated by the dashed vertical lines) with the two-spot model (black solid line) and the evolving single-spot model (red solid line). Lower panel: residuals of the two best fit models; those of the two-spot model are plotted as black diamonds, while those of the evolving single-spot model as red triangles.