Prolog: random permutation

I'm trying to get random permutation with prolog. But the problem is

?- permutation([1,2,3,4],L).

gives always L = [1, 2, 3, 4] as first answer. I could fix this by using the query

?- L1=[1,2,3,4], permutation(L1,L2), dif(L1,L2).

But this gives me always L2 = [1, 2, 4, 3] as first answer.

How can I get a random permutation in SWI Prolog?