Recent observation of a sudden spin down, occurring on a timescale not exceeding two weeks, of the magnetar 1E2259+586 (see Archibald et al. 2013, where this event was dubbed an `anti-glitch') has not still received any interpretation in terms of the standard scenario of pulsar glitches proposed by Anderson and Itoh (1975). Motivated by this observation, here we present a toy model that allows, under certain conditions, for anti-glitches in neutron stars within the standard approach.