A hydraulic system for a working machine is a load sensing system and includes a hydraulic actuator for movement of an implement and a control valve having an inlet valve and an outlet valve for controlling the flow of hydraulic fluid from a pump to the hydraulic actuator and for draining hydraulic fluid from the hydraulic actuator, respectively. The hydraulic system also includes an arrangement for determining the load on the hydraulic actuator. The hydraulic system further includes a valve for disconnecting the flow of hydraulic fluid from the pump to the hydraulic actuator, while allowing another flow of hydraulic fluid to the hydraulic actuator, provided that the determined load on the hydraulic actuator exceeds a threshold value.