diff --git a/openbsc/include/openbsc/ipaccess.h b/openbsc/include/openbsc/ipaccess.h
index 00642ff..0edd81d 100644
--- a/openbsc/include/openbsc/ipaccess.h
+++ b/openbsc/include/openbsc/ipaccess.h
@@ -79,7 +79,7 @@
 int ipaccess_send_id_ack(int fd);
 int ipaccess_send_id_req(int fd);
 
-const char *ipaccess_idtag_name(int tag);
+const char *ipaccess_idtag_name(uint8_t tag);
 int ipaccess_idtag_parse(struct tlv_parsed *dec, unsigned char *buf, int len);
 int ipaccess_parse_unitid(const char *str, u_int16_t *site_id, u_int16_t *bts_id, u_int16_t *trx_id);
 
diff --git a/openbsc/src/libabis/input/ipaccess.c b/openbsc/src/libabis/input/ipaccess.c
index e1e314b..c4c13d7 100644
--- a/openbsc/src/libabis/input/ipaccess.c
+++ b/openbsc/src/libabis/input/ipaccess.c
@@ -100,7 +100,7 @@
 	[IPAC_IDTAG_UNIT]	= "Unit_ID",
 };
 
-const char *ipaccess_idtag_name(int tag)
+const char *ipaccess_idtag_name(uint8_t tag)
 {
 	if (tag >= ARRAY_SIZE(idtag_names))
 		return "unknown";