diff --git a/include/osmocom/gsm/gsup.h b/include/osmocom/gsm/gsup.h
index 890bff3..36e5c84 100644
--- a/include/osmocom/gsm/gsup.h
+++ b/include/osmocom/gsm/gsup.h
@@ -27,6 +27,8 @@
 #include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
 #include <osmocom/crypt/auth.h>
 
+#define OSMO_GSUP_PORT 4222
+
 /*! Maximum nubmer of PDP inside \ref osmo_gsup_message */
 #define OSMO_GSUP_MAX_NUM_PDP_INFO		10 /* GSM 09.02 limits this to 50 */
 /*! Maximum number of auth info inside \ref osmo_gsup_message */