The invention relates to a composition for the oxidation dyeing of keratin fibers, and in particular of human keratin fibers such as the hair, comprising at least one oxidation base and, as coupler, at least one 2-hydroxynaphthalene of formula (I) comprising at least one cationic group Z of formula (II), to their use as couplers for the oxidation dyeing of keratin fibers, to oxidation dyeing processes using them and to novel cationic 2-hydroxynaphthalenes of formula (I′).