The formation of RNA–DNA hybrids results in replicative stress and, as a consequence, the emergence of DNA double-strand breaks (DSBs). Thus, RNA–DNA hybrid formation has been primarily associated with genomic instability. The findings of Ohle et al. now change this view, implicating RNA–DNA hybrids in the maintainance of genome integrity. The authors used Schizosaccharomyces pombe to study the role of RNase H — an enzyme which, among other functions, removes RNA–DNA hybrids. They showed that either removal or overexpression of RNase H reduced the viability of yeast in which DNA DSBs were induced. They then showed that RNA–DNA hybrids form as a result of active transcription at the DSB sites and that their formation, followed by their removal by RNase H, are both important for the proper execution of DSB repair by the homologous recombination pathway.