The invention relates to a method for operating a power output stage (2), in particular an electrical machine, which comprises a bridge circuit (3) with at least one half-bridge (1), wherein the half-bridge (1) has two power semiconductor switches (4, 5) which are connected in series and which are each supplied with an operating control voltage during normal operation in order to set a power voltage, and wherein the power voltage (u4, u5) of the respective power semiconductor switch (4, 5) is detected for the purpose of short-circuit monitoring. In this case, provision is made, in order to check the functioning of the short-circuit monitoring means in a check mode for the power semiconductor switches (4, 5), for a test control voltage which is below the operating control voltage to be set at least temporarily at the same time.