Microorganisms produce numerous specialized metabolites, and the pathways required for the synthesis of these metabolites are encoded by biosynthetic gene clusters (BGCs). Microbial metabolites have important roles in ecological interactions, and various potential industrial and medical applications. For example, bacteriocins are antimicrobial peptides that are produced by many bacteria to inhibit competing strains. Indeed, often these specialized metabolites exert antimicrobial activity, which indicates that they have a crucial role in competitive interactions. However, although much progress has been made in identifying the various types of BGCs and the producing microorganisms, the natural functions of specialized metabolites or their prevalence in microbial communities is less well understood. Interestingly, BGCs have been found in phage genomes, in particular in temperate phages or prophages, which suggests an ecological role of BGC exchange between bacterial strains. In this study, Dragoš, Strube and colleagues report that bacteriocins are encoded in temperate phages, and that they can be transferred between bacterial hosts, which provides a competitive advantage.