diff --git a/include/osmocom/gprs/gprs_ns.h b/include/osmocom/gprs/gprs_ns.h
index 65c7df3..af25825 100644
--- a/include/osmocom/gprs/gprs_ns.h
+++ b/include/osmocom/gprs/gprs_ns.h
@@ -188,6 +188,11 @@
 /* main function for higher layers (BSSGP) to send NS messages */
 int gprs_ns_sendmsg(struct gprs_ns_inst *nsi, struct msgb *msg);
 
+/* Receive incoming NS message from underlying transport layer */
+int gprs_ns_rcvmsg(struct gprs_ns_inst *nsi, struct msgb *msg,
+		   struct sockaddr_in *saddr, enum gprs_ns_ll ll);
+
+
 int gprs_ns_tx_alive(struct gprs_nsvc *nsvc);
 int gprs_ns_tx_alive_ack(struct gprs_nsvc *nsvc);
 int gprs_ns_tx_reset(struct gprs_nsvc *nsvc, uint8_t cause);