Rollover protection for motor vehicles

The roll-over protection system (1) has a roll-over bar (3) that is formed from two clip limbs (4,5) that are connected with each other in a pivoting manner. A drive unit is provided with a defined working space that is connected with a gas generator. A clip end (8) is found in working connection with the working space in the storage position such that a pressure rise in working space produces an adjustment of the clip end from the storage position in the support position. The pressure rise is generated by triggering the gas generator.