A switchable component (1) for a valve train of a combustion engine is provided, such as a roller tappet, with a housing (2), in whose borehole (3) an inner element (4) runs that can move relative to the housing in the axial direction. At least one coupling element (6) is allocated to the inner element (4), wherein this coupling element, in the decoupled case, lies with its outer end (7) directly in front of an annular surface (8) between both components (2, 4) and, in the coupled case, engages in some sections with a driver surface (9) in the borehole (3) of the housing (2), and wherein, between the components (2, 4) there is a lost-motion spring element (10) forcing these components away from each other in the axial direction. As the coupling element (6) there is at least one sickle-shaped ratchet that can pivot outward and that sits at least indirectly in an opening (11) in the outer shell (5) of the inner element (4) and that is connected to the inner element (4) in an articulated way at one end (12). An annular groove is present as a driver surface (9) in the borehole (3) of the housing (2) and the coupling element (6) can pivot outward in the coupling direction via the force of a mechanical spring (13) and can pivot inwardly in the decoupling direction via hydraulic medium guided into the driver surface (9) in front of its outer end (7).