A gas-operated spring with overtravel safety device, comprising: a tubular containment jacket, an end face, an opposite annular portion for closing the tubular jacket and for the passage of a piston rod, a piston rod arranged so as to pass through the annular portion, a chamber for pressurized gas being defined between the tubular jacket, the end face, the annular portion and the piston rod, the gas-operated spring comprising elements for clearly indicating that overtravel for the piston rod has occurred.