A method and control device for correcting an output signal of an exhaust gas sensor in an exhaust gas conduit of an internal combustion engine, a secondary air delivery system for delivering air into the exhaust gas conduit being associated with the exhaust gas conduit upstream from the exhaust gas sensor in the flow direction of the exhaust gas. During a measurement of the output signal of the exhaust gas sensor, air is delivered to the exhaust gas conduit via the secondary air delivery system during a correction phase by way of which a correction of the output signal of the exhaust gas sensor is derived. In this operating mode, a defined oxygen content exists in the gas mixture surrounding said sensor, so that the output signal can be compared with reference values.