The parasite-mediated domestication hypothesis (PMD) assumes an important role of endoparasites in the process of domestication, primarily in the initial phase, i.e. proto-domestication. It predicts that the frequency of domestication syndrome traits in the wild population increases i) with decreasing genetic resistance to parasites and/or ii) with increasing parasite load. This addendum expands on the aspect of genetic resistance/tolerance to parasites, explains the limitations associated with artificial and relaxed selection, and suggests a possible experimental approach to testing PMD.