Overflow in bit fields

can I trust that the C compiler does modulo 2^n each time I access a bit field? Or is there any compiler/optimisation where a code like the one below would not print out Overflow?

struct {
  uint8_t foo:2;
} G;

G.foo = 3;
G.foo++;

if(G.foo == 0) {
  printf("Overflow\n");
}

Thanks in Advance, Florian