Science | Long-terminal-repeat (LTR) retrotransposons are a form of parasitic DNA that can jump around within the host's genome. To avoid damaging resident genes, they have been selected to integrate away from protein-coding sequences. For instance, the fission yeast LTR retrotransposon Tf1 inserts at nucleosome-free regions in gene promoters. Jacobs et al. show that Tf1 is directed to these insertion sites by a specific DNA binding protein, Sap1, which forms DNA replication–fork barriers.