A leakage compensation system in a control device (S) has a fully hydraulic steering system (1) with a supply connection arrangement having a high-pressure connection (P) and a low-pressure connection (T). A working connection arrangement has two working connections (CL, CR), a control section between the supply connection arrangement (P, T) and the working connection arrangement (CL, CR). A control element (2) for activating the control section, a steering member (3) and an auxiliary fluid path (12) has a valve arrangement (A6, A7), through which hydraulic fluid can be supplied or drained off.