Let (S-n: n is an element of N) be a random walk on the nonnegative integers with the convolution structure of the join of the subhypergroups {0,..., n}. It is shown that (for suitable norming constants a(n) --> 0) a(n)S(n) converges in distribution to a nondegenerate limit if and only if the tail of P-s1 is a regularly, but not slowly, varying function.