diff --git a/src/prolog/lib/lists.pl b/src/prolog/lib/lists.pl
index ab3ae5dd..bd3ecd5d 100644
--- a/src/prolog/lib/lists.pl
+++ b/src/prolog/lib/lists.pl
@@ -16,8 +16,7 @@ is_list([_|T]) :- is_list(T).
 
 memberchk(X, Xs) :- member(X, Xs), !.
 
-reverse(Xs, Ys) :- var(Ys), !, reverse(Xs, [], Ys).
-reverse(Ys, Xs) :- reverse(Xs, [], Ys).
+reverse(Xs, Ys) :- reverse(Xs, [], Ys).
 
 reverse([], Ys, Ys).
 reverse([H|T], Ps, Rs) :-