The present invention relates to a device for operating a high-pressure discharge lamp, comprising a switched mode power supply circuit (SMPS) for supplying power to the high pressure discharge lamp from a supply voltage, the power supply circuit comprising a half bridge commutating forward (HBCF) circuit including an inductance^(Lhbcf?), a capacitor circuit of a first capacitor (C_s1) and a second capacitor (C_s2) in series, the lamp (LA) being connectable between the inductance (L_hbcf) and a point (M) between the first and second capacitor (C_s1,C_s2); wherein overvoltage protection means are connected parallel to the lamp, which switch from an off-state with a high resistance operation to an on-state with a low resistance operation when the voltage difference across the protection means exceeds a breakover voltage (V_bo), the breakover voltage (V_bo) being selected to correspond to a predetermined maximum voltage across the first or the second capacitor (C_s1,C_s2).