Replying to myself because it's too late to edit the comment: I'm not sure why people are voting that down. Section 6.2.5 paragraph 9 of the C99 standard state

Replying to myself because it's too late to edit the comment: I'm not sure why people are voting that down. Section 6.2.5 paragraph 9 of the C99 standard states that: A computation involving unsigned operands can never overflow, because a result that cannot be represented by the resulting unsigned integer type is reduced modulo the number that is one greater than the largest value that can be represented by the resulting type.