Child safety seat

The child safety seat (1) for use in a vehicle comprises a seat member (3) configured to hold a child (2), a base member (4) adapted to be attached to a seat (15) of the vehicle, and a locking device (5), wherein the seat member (3) is movably mounted to the base member (4) in such a way to allow the seat member (3) to be transferred from an initial position to a collapsed position by moving the seat member (3) relative to the base member (4) and in such a way that crash-induced forces acting on the child safety seat (1) during a frontal collision of the vehicle tend to transfer the seat member (3) from the initial position to the collapsed position, wherein the locking device (5) is configured to lock the seat member (3) in the initial position and wherein the locking device (5) is designed and arranged to release the seat member (3) from the initial position if the crash-induced forces reach or exceed a given threshold value.