diff --git a/openbsc/include/openbsc/gprs_bssgp.h b/openbsc/include/openbsc/gprs_bssgp.h
index 4afe811..90b945a 100644
--- a/openbsc/include/openbsc/gprs_bssgp.h
+++ b/openbsc/include/openbsc/gprs_bssgp.h
@@ -3,6 +3,10 @@
 
 #include <stdint.h>
 
+/* Section 5.4.1 */
+#define BVCI_SIGNALLING	0x0000
+#define BVCI_PTM	0x0001
+
 /* Section 11.3.26 / Table 11.27 */
 enum bssgp_pdu_type {
 	/* PDUs between RL and BSSGP SAPs */
diff --git a/openbsc/src/gprs/gprs_bssgp.c b/openbsc/src/gprs/gprs_bssgp.c
index 0bc243b..d5ff44d 100644
--- a/openbsc/src/gprs/gprs_bssgp.c
+++ b/openbsc/src/gprs/gprs_bssgp.c
@@ -186,7 +186,7 @@
 	struct bssgp_bvc_ctx *ptp_ctx;
 
 	bvci = ntohs(*(uint16_t *)TLVP_VAL(tp, BSSGP_IE_BVCI));
-	if (bvci == 0) {
+	if (bvci == BVCI_SIGNALLING) {
 		/* 8.3.2: Signalling BVC shall never be blocked */
 		LOGP(DBSSGP, LOGL_ERROR, "NSEI=%u/BVCI=%u "
 			"received block for signalling BVC!?!\n",
@@ -216,7 +216,7 @@
 	struct bssgp_bvc_ctx *ptp_ctx;
 
 	bvci = ntohs(*(uint16_t *)TLVP_VAL(tp, BSSGP_IE_BVCI));
-	if (bvci == 0) {
+	if (bvci == BVCI_SIGNALLING) {
 		/* 8.3.2: Signalling BVC shall never be blocked */
 		LOGP(DBSSGP, LOGL_ERROR, "NSEI=%u/BVCI=%u "
 			"received unblock for signalling BVC!?!\n",
@@ -517,9 +517,9 @@
 			     msgb_bssgp_len(msg));
 	}
 
-	if (ns_bvci == 1)
+	if (ns_bvci == BVCI_SIGNALLING)
 		rc = gprs_bssgp_rx_sign(msg, &tp, bctx);
-	else if (ns_bvci == 2)
+	else if (ns_bvci == BVCI_PTM)
 		rc = bssgp_tx_status(BSSGP_CAUSE_PDU_INCOMP_FEAT, NULL, msg);
 	else
 		rc = gprs_bssgp_rx_ptp(msg, &tp, bctx);
@@ -542,7 +542,7 @@
 	uint16_t nsei = msgb_nsei(msg);
 
 	/* Identifiers from UP: TLLI, BVCI, NSEI (all in msgb->cb) */
-	if (bvci < 2) {
+	if (bvci <= BVCI_PTM ) {
 		LOGP(DBSSGP, LOGL_ERROR, "Cannot send DL-UD to BVCI %u\n",
 			bvci);
 		return -EINVAL;