--- a/src/pt-misc.cc
+++ b/src/pt-misc.cc
@@ -302,10 +302,13 @@
 }
 
 Octave_object
-tree_parameter_list::convert_to_const_vector (void)
+tree_parameter_list::convert_to_const_vector (tree_va_return_list *vr_list)
 {
   int nout = length ();
 
+  if (vr_list)
+    nout += vr_list->length ();
+
   Octave_object retval;
   retval.resize (nout);
 
@@ -321,6 +324,15 @@
       i++;
     }
 
+  if (vr_list)
+    {
+      for (p = vr_list->first (); p != 0; vr_list->next (p))
+	{
+	  retval(i) = vr_list->operator () (p);
+	  i++;
+	}
+    }
+
   return retval;
 }