An arrangement in a support leg (1) for a load carrier, such as a loading platform, said support leg (1) being connected to a hinge means (2) for movement between an inwards folded and an outwards folded position merely by pivoting. The device comprises a locking device for locking the support leg (1) in the outwards folded position thereof, said locking device comprising a first locking means (4) mounted on the support leg (1) in such a manner as to be movable along the longitudinal axis (6) thereof, and a second locking means (8) matching the first locking means (4) and formed in the hinge means (2). The first locking means (4) is arranged, by cooperation with the hinge means (2), to be displaced along the longitudinal axis (6) of the support leg (1) upon pivoting outwards of the support leg (1), for engagement with the second locking means (8) and thus effect said locking.