diff --git a/src/gb/gprs_ns.c b/src/gb/gprs_ns.c
index 0780f2bbd..1281c9f4c 100644
--- a/src/gb/gprs_ns.c
+++ b/src/gb/gprs_ns.c
@@ -1413,9 +1413,15 @@ int gprs_ns_process_msg(struct gprs_ns_inst *nsi, struct msgb *msg,
 		/* Section 7.2: unblocking procedure */
 		LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS UNBLOCK\n", (*nsvc)->nsei);
 		ns_mark_unblocked(*nsvc);
+		/* This UNBLOCK_ACK message will cause our peer to move us into NS_UNBLOCKED state. */
 		rc = gprs_ns_tx_simple(*nsvc, NS_PDUT_UNBLOCK_ACK);
 		if (rc < 0)
 			break;
+		/*
+		 * UNBLOCK_ACK has been transmitted.
+		 * Signal handlers may send additional messages following UNBLOCK_ACK under
+		 * the assumption that NS is now in UNBLOCKED state at our peer's end.
+		 */
 		ns_osmo_signal_dispatch(*nsvc, S_NS_UNBLOCK, 0);
 		break;
 	case NS_PDUT_UNBLOCK_ACK: