diff --git a/channels/chan_pjsip.c b/channels/chan_pjsip.c
index a560d77063202072e9464b0361fc5a1e4013ae7f..0fbfd9ea5645917d64932184afb5606c4aa942e4 100644
--- a/channels/chan_pjsip.c
+++ b/channels/chan_pjsip.c
@@ -1429,8 +1429,6 @@ static void clear_session_and_channel(struct ast_sip_session *session, struct as
 
 static int hangup(void *data)
 {
-	pj_status_t status;
-	pjsip_tx_data *packet = NULL;
 	struct hangup_data *h_data = data;
 	struct ast_channel *ast = h_data->chan;
 	struct ast_sip_channel_pvt *channel = ast_channel_tech_pvt(ast);
@@ -1438,12 +1436,19 @@ static int hangup(void *data)
 	struct ast_sip_session *session = channel->session;
 	int cause = h_data->cause;
 
-	if (!session->defer_terminate &&
-		((status = pjsip_inv_end_session(session->inv_session, cause ? cause : 603, NULL, &packet)) == PJ_SUCCESS) && packet) {
-		if (packet->msg->type == PJSIP_RESPONSE_MSG) {
-			ast_sip_session_send_response(session, packet);
-		} else {
-			ast_sip_session_send_request(session, packet);
+	if (!session->defer_terminate) {
+		pj_status_t status;
+		pjsip_tx_data *packet = NULL;
+
+		if (session->inv_session->state == PJSIP_INV_STATE_NULL) {
+			pjsip_inv_terminate(session->inv_session, cause ? cause : 603, PJ_TRUE);
+		} else if (((status = pjsip_inv_end_session(session->inv_session, cause ? cause : 603, NULL, &packet)) == PJ_SUCCESS)
+			&& packet) {
+			if (packet->msg->type == PJSIP_RESPONSE_MSG) {
+				ast_sip_session_send_response(session, packet);
+			} else {
+				ast_sip_session_send_request(session, packet);
+			}
 		}
 	}
 
diff --git a/res/res_pjsip_session.c b/res/res_pjsip_session.c
index 04220094fe54cd398666193d62931a0c6c04b78d..caaed317a5cb7a61522405bf52e7fa7582799478 100644
--- a/res/res_pjsip_session.c
+++ b/res/res_pjsip_session.c
@@ -1826,14 +1826,20 @@ static int session_end(struct ast_sip_session *session)
 static void session_inv_on_state_changed(pjsip_inv_session *inv, pjsip_event *e)
 {
 	struct ast_sip_session *session = inv->mod_data[session_module.id];
+	pjsip_event_id_e type;
 
-	print_debug_details(inv, NULL, e);
+	if (e) {
+		print_debug_details(inv, NULL, e);
+		type = e->type;
+	} else {
+		type = PJSIP_EVENT_UNKNOWN;
+	}
 
 	if (!session) {
 		return;
 	}
 
-	switch(e->type) {
+	switch(type) {
 	case PJSIP_EVENT_TX_MSG:
 		handle_outgoing(session, e->body.tx_msg.tdata);
 		break;