diff --git a/openbsc/include/openbsc/gsm_data_shared.h b/openbsc/include/openbsc/gsm_data_shared.h
index 3bf05e4..ae9e7d8 100644
--- a/openbsc/include/openbsc/gsm_data_shared.h
+++ b/openbsc/include/openbsc/gsm_data_shared.h
@@ -676,6 +676,9 @@
 	int num_trx;
 	struct llist_head trx_list;
 
+	/* SI compatibility hacks */
+	int force_combined_si;
+
 #ifdef ROLE_BSC
 	/* Abis NM queue */
 	struct llist_head abis_queue;