The invention relates to a safety device used in case a vehicle rolls over, said safety device comprising: at least two curved bars (1, 1′) that are movable from a retracted position to a deployed position in case a rollover; a pre-stressed system for deploying each bar; a trigger system; and at least one locking member (22, 22′); wherein device the first end of each bar (1, 1′) is hinged to a common central plate (4) so that each of said two bars (1, 1′) extends on a respective side of said plate, from a common face of said plate, a control, locking, and releasing device for controlling, locking, and releasing each bar (1, 1′) being provided on the same face of said plate (4), the plate (4) being designed to be fixed to a structural element of the vehicle. The invention also relates to a vehicle including such a device.