Do 16" wheels fit the spare wheel holder underneath?

[CB55]

I haven't had a need, thankfully, to use my spare, but today I took it out to check it before a trip... the tyre was firm but the rim was rotten. I don't think it has ever been used. Anyhow, I have 16" rims on the van, and the spare is a 15". I'm ditching the current spare but before I buy a 16" spare, I wondered if it will fit the under-carriage holder? Can anyone confirm? Thanks