The invention relates to a device for driving a coolant pump (2) for the coolant circuit of an internal combustion engine in a motor vehicle comprising a drive train that encompasses a drive wheel (7), a viscous coupling (11), and a drive shaft (3). The inventive driving device is provided with a second coupling (15) which is embodied as a clutch and can be connected to the drive train parallel to the viscous coupling (11), resulting in increased redundancy and two-step rev control.