Indonesian Citizenship

Hi to you all. Does anyone know the answer to the following: I have two kids who have both British and Indonesian passports. Indonesian law states that when they are 18 they must choose which nationality they want to keep as Indonesia does not allow dual nationalities. My question is, if I decided to change my own nationality and became an Indonesian citizen, would my children have to forfeit their British passport? The more I think about it, the more I am confident they won't have to, but I am not sure... This is only a hypothetical question - the idea just recently occurred to me, so I thought I would investigate more. Thanks in advance for any reply.