On the basis of whole genome comparisons of Streptomyces griseorubiginosus and Streptomyces phaeopurpureus it could by shown that these two species are subjective synonyms. The names of both species have been published in the Approved Lists of Bacterial Names and, in such a case, normally Rule 24b (1) of the Prokaryotic Code applies, which reads: 'If two names compete for priority and if both names date from 1 January 1980 on an Approved List, the priority shall be determined by the date of the original publication of the name before 1 January 1980'. Streptomyces griseorubiginosus and Streptomyces phaeopurpureus were both effectively published in 1957, and for both publications, the exact date cannot be obtained. In this case a further statement of Rule 24 applies, which reads: 'If the names or epithets are of the same date, the author who first unites the taxa has the right to choose one of them, and his choice must be followed.' Hence we propose that Streptomyces phaeopurpureus is a later heterotypic subjective synonym of Streptomyces griseorubiginosus.