A method for operating a DC-DC voltage converter, which, at an output, adjusts an output variable to a prescribed setpoint value by way of a regulator unit. Depending on an actual value of the output variable, the regulator unit sets a duty cycle of a pulse-width modulation. The regulator unit has an operating parameter for providing the pulse-width modulation. The operating parameter is variable and is changed to a new parameter value by a control apparatus which determines whether, with the unchanged setpoint value and the new parameter value, the regulator unit sets a lower duty cycle for adjusting the output variable than before the setting of the new parameter value. In that case, the new parameter value is retained. Otherwise it is changed back. The operating parameter that is varied by the new parameter value is a period of the pulse-width modulation and/or an edge steepness of switching edges.