diff --git a/include/osmocom/msc/iucs.h b/include/osmocom/msc/iucs.h
index b7d6064..a48a316 100644
--- a/include/osmocom/msc/iucs.h
+++ b/include/osmocom/msc/iucs.h
@@ -1,7 +1,10 @@
 #pragma once
 
+#include <osmocom/msc/transaction.h>
+
 int gsm0408_rcvmsg_iucs(struct gsm_network *network, struct msgb *msg,
 			uint16_t *lac);
 
 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);