diff --git a/include/osmocom/gprs/gprs_bssgp.h b/include/osmocom/gprs/gprs_bssgp.h
index c0b3f65..b70487c 100644
--- a/include/osmocom/gprs/gprs_bssgp.h
+++ b/include/osmocom/gprs/gprs_bssgp.h
@@ -14,6 +14,7 @@
 struct msgb *bssgp_msgb_alloc(void);
 struct msgb *bssgp_msgb_copy(const struct msgb *msg, const char *name);
 const char *bssgp_cause_str(enum gprs_bssgp_cause cause);
+const char *bssgp_pdu_str(enum bssgp_pdu_type pdu);
 /* Transmit a simple response such as BLOCK/UNBLOCK/RESET ACK/NACK */
 int bssgp_tx_simple_bvci(uint8_t pdu_type, uint16_t nsei,
 			 uint16_t bvci, uint16_t ns_bvci);