The Drosophila melanogaster abdominal epithelium provides a good model for understanding how postmitotic diploid cells contribute to repair upon tissue damage. Losick et al. show that, after puncture wounds are made in this system, DNA replication without cell division is induced in cells near the wound site, which results in polyploidy. In addition, cells surrounding the wound fuse to form multinucleate cells. The authors postulate that polyploidization is required to restore the tissue mass that is lost upon injury and that cell fusion speeds up re-epithelialization.