diff --git a/include/osmocom/msc/iucs.h b/include/osmocom/msc/iucs.h
index a48a316..8b22104 100644
--- a/include/osmocom/msc/iucs.h
+++ b/include/osmocom/msc/iucs.h
@@ -8,3 +8,5 @@
 struct gsm_subscriber_connection *subscr_conn_lookup_iu(struct gsm_network *network,
 							struct ranap_ue_conn_ctx *ue);
 int iu_rab_act_cs(struct gsm_trans *trans);
+
+uint32_t iu_get_conn_id(const struct ranap_ue_conn_ctx *ue);