A check valve comprising a valve housing, which comprises an inlet, an outlet, and a valve channel. The valve channel connects the inlet to the outlet and has a valve seat. The check valve further comprises a closure part, which cooperates with the valve seat, and a tappet bearing the closure part. An end of the tappet which is remote from the closure part bears a control piston, which together with a cylinder wall defines a control chamber, which is connected a control connection. The control chamber is connected to the valve channel by means of a connection channel.