Earlier, all members of the orders Apodiformes, Aegotheliformes, Nyctibiiformes, Podargiformes, and Steatornithiformes were lumped alongside nightjars in the Caprimulgiformes. In 2021, the International Ornithological Congress redefined the order Caprimulgiformes as only applying to nightjars while potoos, frogmouths, oilbirds, and owlet-nightjars were all reclassified into their own orders.