diff --git a/libs/sofia-sip/libsofia-sip-ua/nua/nua_session.c b/libs/sofia-sip/libsofia-sip-ua/nua/nua_session.c
index 93feb9c510..f2214e8f47 100644
--- a/libs/sofia-sip/libsofia-sip-ua/nua/nua_session.c
+++ b/libs/sofia-sip/libsofia-sip-ua/nua/nua_session.c
@@ -1089,9 +1089,14 @@ int nua_invite_client_ack(nua_client_request_t *cr, tagi_t const *tags)
   char const *phrase = "OK", *reason = NULL;
   char const *invite_branch;
 
-  assert(ds->ds_leg);
   assert(cr->cr_orq);
 
+  if (!ds->ds_leg) {
+	  nta_outgoing_destroy(cr->cr_orq);
+	  return -1;
+  }
+
+
   msg = nta_outgoing_getrequest(cr->cr_orq);
   sip = sip_object(msg);
   if (!msg)