--- chan_iax2.c.dist	2011-09-12 23:25:42.000000000 +1000
+++ chan_iax2.c	2011-12-13 20:12:58.000000000 +1100
@@ -5737,8 +5737,10 @@
 		tmp->caller.ani.number.str = ast_strdup(i->cid_num);
 	}
 	tmp->dialed.number.str = ast_strdup(i->dnid);
-	tmp->redirecting.from.number.valid = 1;
-	tmp->redirecting.from.number.str = ast_strdup(i->rdnis);
+	if (!ast_strlen_zero(i->rdnis)) {
+		tmp->redirecting.from.number.valid = 1;
+		tmp->redirecting.from.number.str = ast_strdup(i->rdnis);
+	}
 	tmp->caller.id.name.presentation = i->calling_pres;
 	tmp->caller.id.number.presentation = i->calling_pres;
 	tmp->caller.id.number.plan = i->calling_ton;