Adidas Sleek - size up?

[Catintwohats]

These are so narrow fitting. If anyone has them, have you sized up and, if so, a full size or half a size?

Thanks.

I'm a size 8 and I need a 9 in Sleeks which is unfortunate as they're hard to come by. Definitely a full size up!

Thanks @TheVampiresWife, that's good to know.