diff --git a/include/re_sip.h b/include/re_sip.h
index d638ea9..c7db95e 100644
--- a/include/re_sip.h
+++ b/include/re_sip.h
@@ -306,6 +306,7 @@ int  sip_dialog_fork(struct sip_dialog **dlgp, struct sip_dialog *odlg,
 int  sip_dialog_update(struct sip_dialog *dlg, const struct sip_msg *msg);
 bool sip_dialog_rseq_valid(struct sip_dialog *dlg, const struct sip_msg *msg);
 const char *sip_dialog_callid(const struct sip_dialog *dlg);
+uint32_t sip_dialog_lseq(const struct sip_dialog *dlg);
 bool sip_dialog_established(const struct sip_dialog *dlg);
 bool sip_dialog_cmp(const struct sip_dialog *dlg, const struct sip_msg *msg);
 bool sip_dialog_cmp_half(const struct sip_dialog *dlg,
diff --git a/src/sip/dialog.c b/src/sip/dialog.c
index 45869a5..1516a8a 100644
--- a/src/sip/dialog.c
+++ b/src/sip/dialog.c
@@ -511,6 +511,12 @@ const char *sip_dialog_callid(const struct sip_dialog *dlg)
 }
 
 
+uint32_t sip_dialog_lseq(const struct sip_dialog *dlg)
+{
+	return dlg ? dlg->lseq : 0;
+}
+
+
 bool sip_dialog_established(const struct sip_dialog *dlg)
 {
 	return dlg && dlg->rtag;
diff --git a/src/sipevent/listen.c b/src/sipevent/listen.c
index 02254a5..0efae54 100644
--- a/src/sipevent/listen.c
+++ b/src/sipevent/listen.c
@@ -37,7 +37,8 @@ static void destructor(void *arg)
 
 
 static bool event_cmp(const struct sipevent_event *evt,
-		      const char *event, const char *id)
+		      const char *event, const char *id,
+		      int32_t refer_cseq)
 {
 	if (pl_strcmp(&evt->event, event))
 		return false;
@@ -45,9 +46,16 @@ static bool event_cmp(const struct sipevent_event *evt,
 	if (!pl_isset(&evt->id) && !id)
 		return true;
 
-	if (!pl_isset(&evt->id) || !id)
+	if (!pl_isset(&evt->id))
 		return false;
 
+	if (!id) {
+		if (refer_cseq >= 0 && (int32_t)pl_u32(&evt->id) == refer_cseq)
+			return true;
+
+		return false;
+	}
+
 	if (pl_strcmp(&evt->id, id))
 		return false;
 
@@ -70,7 +78,8 @@ static bool sub_cmp_handler(struct le *le, void *arg)
 	struct sipsub *sub = le->data;
 
 	return sip_dialog_cmp(sub->dlg, cmp->msg) &&
-		(!cmp->evt || event_cmp(cmp->evt, sub->event, sub->id));
+		(!cmp->evt || event_cmp(cmp->evt, sub->event, sub->id,
+					sub->refer_cseq));
 }
 
 
@@ -81,7 +90,8 @@ static bool sub_cmp_half_handler(struct le *le, void *arg)
 
 	return sip_dialog_cmp_half(sub->dlg, cmp->msg) &&
 		!sip_dialog_established(sub->dlg) &&
-		(!cmp->evt || event_cmp(cmp->evt, sub->event, sub->id));
+		(!cmp->evt || event_cmp(cmp->evt, sub->event, sub->id,
+					sub->refer_cseq));
 }
 
 
@@ -175,6 +185,15 @@ static void notify_handler(struct sipevent_sock *sock,
 		(void)sip_dialog_update(sub->dlg, msg);
 	}
 
+	if (sub->refer_cseq >= 0 && !sub->id && pl_isset(&event.id)) {
+
+		err = pl_strdup(&sub->id, &event.id);
+		if (err) {
+			(void)sip_treply(NULL, sip, msg, 500, strerror(err));
+			return;
+		}
+	}
+
 	re_printf("notify: %s (%r)\n", sipevent_substate_name(state.state),
 		  &state.params);
 
diff --git a/src/sipevent/sipevent.h b/src/sipevent/sipevent.h
index 1f581ca..e171d4b 100644
--- a/src/sipevent/sipevent.h
+++ b/src/sipevent/sipevent.h
@@ -46,6 +46,7 @@ struct sipsub {
 	sipevent_notify_h *notifyh;
 	sipevent_close_h *closeh;
 	void *arg;
+	int32_t refer_cseq;
 	uint32_t expires;
 	uint32_t failc;
 	bool subscribed;
diff --git a/src/sipevent/subscribe.c b/src/sipevent/subscribe.c
index 7ee472c..1ac12d3 100644
--- a/src/sipevent/subscribe.c
+++ b/src/sipevent/subscribe.c
@@ -306,6 +306,8 @@ static int request(struct sipsub *sub, bool reset_ls)
 
 	if (sub->refer) {
 
+		sub->refer_cseq = sip_dialog_lseq(sub->dlg);
+
 		return sip_drequestf(&sub->req, sub->sip, true, "REFER",
 				     sub->dlg, 0, sub->auth,
 				     send_handler, response_handler, sub,
@@ -396,6 +398,7 @@ static int sipsub_alloc(struct sipsub **subp, struct sipevent_sock *sock,
 			goto out;
 	}
 
+	sub->refer_cseq = -1;
 	sub->refer   = refer;
 	sub->sock    = mem_ref(sock);
 	sub->sip     = mem_ref(sock->sip);