The invention relates to a protective circuit for the protection of the user from overvoltage and overcurrent, in particular for telecommunication installations. Prior art protective circuits comprise a fuse connected into the line connection, and a surge arrester with a heat-sensitive protection device, forming a cross path between the current path of the line connection and the earth conductor, the heat-sensitive protection device disconnecting the cross path in case of excessive power, and connecting it to the earth conductor.In the protective circuit according to the invention, a response of the heat-sensitive protection device (5, 6) will cause disconnection of the cross path of the surge arrester (1, 2) and closing of a short-circuit cross path (7, 8) behind the fuse (3, 4) between the line connection (a, a'; b, b') and the earth conductor (E). The protective circuit can be accommodated in a miniature plug for application in telecommunication installations.