diff --git a/packages/CLPBN/clpbn/aggregates.yap b/packages/CLPBN/clpbn/aggregates.yap
index 3c189756d..81978a2af 100644
--- a/packages/CLPBN/clpbn/aggregates.yap
+++ b/packages/CLPBN/clpbn/aggregates.yap
@@ -52,10 +52,11 @@ cpt_average(AllVars, Key, Els0, Tab, Vs, NewVs) :-
 	cpt_average(AllVars, Key, Els0, 1.0, Tab, Vs, NewVs).
 
 % support variables with evidence from domain. This should make everyone's life easier.
-cpt_average([Ev|Vars], Key, Els0, Softness, pf(Els0, MAT, NewParents), Vs, NewVs) :-
+cpt_average([Ev|Vars], Key, Els0, Softness, p(Els0, TAB, NewParents), Vs, NewVs) :-
 	find_evidence(Vars, 0, TotEvidence, RVars),
 	build_avg_table(RVars, Vars, Els0, Key, TotEvidence, Softness, MAT0, NewParents0, Vs, IVs),
-	include_qevidence(Ev, MAT0, MAT, NewParents0, NewParents, Vs, IVs, NewVs).
+	include_qevidence(Ev, MAT0, MAT, NewParents0, NewParents, Vs, IVs, NewVs),
+	matrix_to_list(MAT, TAB).
 
 % find all fixed kids, this simplifies significantly the function.
 find_evidence([], TotEvidence, TotEvidence, []).