Discussions of the psycholinguistic significance of regularity in inflectional morphology generally deal with languages in which regular forms can be clearly identified and revolve around whether there are distinct processing mechanisms for regular and irregular forms. We present a detailed description of Dinka's notoriously irregular noun number inflection and suggest that no pattern can usefully be designated as regular. Psycholinguistic studies of Dinka would make a valuable contribution to our understanding of inflectional morphology crosslinguistically.