diff --git a/include/osmocom/bsc/rest_octets.h b/include/osmocom/bsc/rest_octets.h
index 876e0ab..ba25b6d 100644
--- a/include/osmocom/bsc/rest_octets.h
+++ b/include/osmocom/bsc/rest_octets.h
@@ -9,6 +9,7 @@
 /* generate SI1 rest octets */
 int rest_octets_si1(uint8_t *data, uint8_t *nch_pos, int is1800_net);
 int rest_octets_si2quater(uint8_t *data, struct gsm_bts *bts);
+int rest_octets_si2ter(uint8_t *data);
 int rest_octets_si6(uint8_t *data, bool is1800_net);
 
 struct gsm48_si_selection_params {