Abstract: A hydrostatic positive displacement machine (2) is operated in a closed circuit and delivers hydraulic fluid into a working circuit. The displacement volume is varied by a control device (6) having a variable displacement piston device (7). The machine (2) has a swivel-back device (40) which, in the event of a decrease of the feed pressure from the feed pressure source (11), guarantees actuation of the machine (2) toward a reduction of the displacement volume. The swivel-back device (40) includes at least one pressure sequence valve (41), which is in communication on the input side with the working circuit of the machine (2). In the event of a decrease in the feed pressure from the feed pressure source (11) below a limit pressure, the pressure sequence valve (41) makes it possible to supply the control device (6) of the machine (2) with hydraulic fluid from the working circuit.