Stem cells often divide asymmetrically both to self-renew and to produce daughter cells that enter differentiation. However, it is not known how epigenetic information is transmitted in such divisions. Here the authors tracked 'old' histones (those that were in place before mitosis) and 'new' histones using a system that labelled histone H3 with a different colour before and after heat shock in fruitfly male germ stem cells (GSCs). They found that old H3 (but not the variant histone H3.3) is preferentially distributed to the renewed GSC rather than to the daughter gonialblast cell; this may enable stem-cell-specific epigenetic information to be retained.