Abstract: The present invention relates to a linear actuator with an improved electric motor. In particular, the invention focuses on improved technical solutions for braking or locking of a rotating electric motor by using an electro-mechanical locking mechanism. The mechanism uses a solenoid having a nonrotating locking element, which is displaceable by solenoid action and arranged to engage with a rotating locking element. In particular, solutions have been found in which a surprisingly small solenoid with a much-reduced requirement on stroke length may be deployed to effectively unidirectionally or bidirectionally lock against rotation of the motor.