A device for controlling a motor of an electric bicycle. The device includes a control electronics system that is set up to control a torque of the motor in a normal operating mode based on an acquired driver torque; to detect during normal operation whether, at the current motor torque, no rotation of the motor is taking place even though a driver torque is being exerted, and to control the motor to continue to provide the motor torque in a blocking operating mode if it has been detected that at the present motor torque no rotation of the motor is taking place even though a driver torque is being exerted.