diff --git a/pl/arith.yap b/pl/arith.yap
index 25c88266c..c18411ab5 100644
--- a/pl/arith.yap
+++ b/pl/arith.yap
@@ -37,10 +37,9 @@ do_not_compile_expressions :- set_value('$c_arith',[]).
 
 
 '$do_c_built_in'(G, M, OUT) :- var(G), !,
-	'$do_c_built_in'(call(G), M, OUT).
-'$do_c_built_in'(Mod:G, _, GN) :- !,
-	'$do_c_built_in'(G, Mod, GN0),
-	(GN0 = (_,_) -> GN = GN0 ; GN = Mod:GN0).
+	'$do_c_built_metacall'(G, M, OUT).
+'$do_c_built_in'(Mod:G, _, OUT) :- !,
+	'$do_c_built_metacall'(G, Mod, OUT).
 '$do_c_built_in'(\+ G, _, OUT) :-
 	nonvar(G),
 	G = (A = B),