A name with non-English character

Hello!

I got my voucher today and noticed that the letter Ö in my name has been replaced with the letter O. Could it cause problems, because my name on the passport has an Ö in it. I expected that this would happen (my plane tickets always have O on them too, can cause problems with automated systems but nothing that cannot be solved) and I guess it shouldn't be a huge issue but this is my first time purchasing a JR pass so I have no idea how strict they are with these kind of things.