Burdened by Purpose

If your roll bonus to CHARM rolls is less
than +2, it becomes +2.
If your roll bonus to CHARM rolls was already
+2, or if it becomes +2 due to some other
ability or effect, you instead roll the next highest
dice class for CHARM rolls. (For example, if your
current dice class was 2d8, you would instead
roll 1d8 AND 1d10).