diff --git a/pl/yapor.yap b/pl/yapor.yap
index 24b54c631..bf33b5ccb 100644
--- a/pl/yapor.yap
+++ b/pl/yapor.yap
@@ -161,7 +161,7 @@ parallel_once(Goal) :-
 
 '$parallel_once_query'(Goal) :-
    '$c_yapor_start', 
-   '$execute'(Goal), !,
+   '$execute'(once(Goal)),
     recordz(parallel_once,Goal,_),
     fail.
 '$parallel_once_query'(_).