diff --git a/library/builtins.pl b/library/builtins.pl
index 619f7fe88..b41ad41c7 100644
--- a/library/builtins.pl
+++ b/library/builtins.pl
@@ -712,11 +712,12 @@
 
 % Debugging...
 
-print_goals_([]).
-print_goals_([Goal|Goals]) :-
+print_goals_(_, []).
+print_goals_(Any, [Goal|Goals]) :-
+	(Any -> write(', ') ; true),
 	write(Goal),
 	(Goals == [] -> true ;	write(', ')),
-	print_goals_(Goals).
+	print_goals_(false, Goals).
 
 dump_attvars_([], []).
 dump_attvars_([Var|Vars], [Gs|Rest]) :-
@@ -724,13 +725,13 @@
 	Var = Var2,
 	dump_attvars_(Vars, Rest).
 
-dump_attvars :-
+dump_attvars(Any) :-
 	'$list_attributed'(Vs0),
 	sort(Vs0, Vs),
 	dump_attvars_(Vs, Gs0),
 	flatten(Gs0, Gs1),
 	sort(Gs1, Gs),
-	print_goals_(Gs).
+	print_goals_(Any, Gs).
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
diff --git a/src/toplevel.c b/src/toplevel.c
index 75c3cb33a..040e53109 100644
--- a/src/toplevel.c
+++ b/src/toplevel.c
@@ -464,7 +464,7 @@ void dump_vars(query *q, bool partial)
 	bool any_atts = any_attributed(q);
 
 	if (any && any_atts)
-		fprintf(stdout, "%s", ", ");
+		fprintf(stdout, "%s", "");
 	else if (any_atts && !q->is_redo)
 		fprintf(stdout, "%s", "   ");
 	else if (any_atts)
@@ -477,10 +477,11 @@ void dump_vars(query *q, bool partial)
 		q->variable_names = vlist;
 		q->variable_names_ctx = q->st.curr_frame;
 		q->tab_idx = 0;
-		cell p1;
-		make_atom(&p1, new_atom(q->pl, "dump_attvars"));
-		cell *tmp = prepare_call(q, NOPREFIX_LEN, &p1, q->st.curr_frame, 1);
-		pl_idx nbr_cells = p1.nbr_cells;
+		cell p1[2];
+		make_struct(p1+0, new_atom(q->pl, "dump_attvars"), NULL, 1, 1);
+		make_atom(p1+1, any ? g_true_s : g_false_s);
+		cell *tmp = prepare_call(q, NOPREFIX_LEN, p1, q->st.curr_frame, 1);
+		pl_idx nbr_cells = p1->nbr_cells;
 		make_end(tmp+nbr_cells);
 		q->st.curr_instr = tmp;
 		q->in_attvar_print = true;