Indicator Buzzer

I know some may hate the idea of having a buzzer fitted to the indicators but I have had them on every bike and they actually attract attention of cyclists and pedestrians at junctions and on the odd occasion remind me to switch them off. The one I bought from Maplins some years ago has deceased after many years of faithful service ( many years divided by £2.50 = good value). I replaced the old one with a 12v buzzer I bought from eBay. Having wired it in the same way with the ignition on and indicators on it works fine. With the engine on and indicators on it is ok but once the indicators are off it continues to sound loudly. Am I right in assuming that this buzzer is different inside to my old one and if so does it need a diode fitting, if so where and in what direction? Yes I know I don’t actually need one but each to their own. Thanks