The Rufous-chested Dotterel Charadrius modestus has been shown to be deeply diverged sister taxon to the dissimilar-looking Phegornis mitchellii (Černý and Natale 2022), and the two are best retained in separate genera. Zonibyx is resurrected for modestus, and hence Charadrius modestus becomes Zonibyx modestus, as in Peters (1934) and the first edition of Clements.