diff --git a/openbsc/include/openbsc/transaction.h b/openbsc/include/openbsc/transaction.h
index 795b9cd..82891b8 100644
--- a/openbsc/include/openbsc/transaction.h
+++ b/openbsc/include/openbsc/transaction.h
@@ -66,7 +66,8 @@
 struct gsm_trans *trans_find_by_callref(struct gsm_network *net,
 					uint32_t callref);
 
-struct gsm_trans *trans_alloc(struct gsm_subscriber *subscr,
+struct gsm_trans *trans_alloc(struct gsm_network *net,
+			      struct gsm_subscriber *subscr,
 			      uint8_t protocol, uint8_t trans_id,
 			      uint32_t callref);
 void trans_free(struct gsm_trans *trans);
diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c
index ede6db3..ac1e916 100644
--- a/openbsc/src/libmsc/gsm_04_08.c
+++ b/openbsc/src/libmsc/gsm_04_08.c
@@ -3078,7 +3078,7 @@
 						GSM48_CC_CAUSE_DEST_OOO);
 		}
 		/* Create transaction */
-		trans = trans_alloc(subscr, GSM48_PDISC_CC, 0xff, data->callref);
+		trans = trans_alloc(net, subscr, GSM48_PDISC_CC, 0xff, data->callref);
 		if (!trans) {
 			DEBUGP(DCC, "No memory for trans.\n");
 			subscr_put(subscr);
@@ -3262,7 +3262,8 @@
 		DEBUGP(DCC, "Unknown transaction ID %x, "
 			"creating new trans.\n", transaction_id);
 		/* Create transaction */
-		trans = trans_alloc(conn->subscr, GSM48_PDISC_CC,
+		trans = trans_alloc(conn->bts->network, conn->subscr,
+				    GSM48_PDISC_CC,
 				    transaction_id, new_callref++);
 		if (!trans) {
 			DEBUGP(DCC, "No memory for trans.\n");
diff --git a/openbsc/src/libmsc/gsm_04_11.c b/openbsc/src/libmsc/gsm_04_11.c
index bc9d59e..9941e6b 100644
--- a/openbsc/src/libmsc/gsm_04_11.c
+++ b/openbsc/src/libmsc/gsm_04_11.c
@@ -765,7 +765,8 @@
 
 	if (!trans) {
 		DEBUGP(DLSMS, " -> (new transaction)\n");
-		trans = trans_alloc(conn->subscr, GSM48_PDISC_SMS,
+		trans = trans_alloc(conn->bts->network, conn->subscr,
+				    GSM48_PDISC_SMS,
 				    transaction_id, new_callref++);
 		if (!trans) {
 			DEBUGP(DLSMS, " -> No memory for trans\n");
@@ -838,7 +839,8 @@
 	DEBUGP(DLSMS, "send_sms_lchan()\n");
 
 	/* FIXME: allocate transaction with message reference */
-	trans = trans_alloc(conn->subscr, GSM48_PDISC_SMS,
+	trans = trans_alloc(conn->bts->network, conn->subscr,
+			    GSM48_PDISC_SMS,
 			    transaction_id, new_callref++);
 	if (!trans) {
 		LOGP(DLSMS, LOGL_ERROR, "No memory for trans\n");
diff --git a/openbsc/src/libmsc/transaction.c b/openbsc/src/libmsc/transaction.c
index 5621067..2101ae9 100644
--- a/openbsc/src/libmsc/transaction.c
+++ b/openbsc/src/libmsc/transaction.c
@@ -61,12 +61,12 @@
 	return NULL;
 }
 
-struct gsm_trans *trans_alloc(struct gsm_subscriber *subscr,
+struct gsm_trans *trans_alloc(struct gsm_network *net,
+			      struct gsm_subscriber *subscr,
 			      uint8_t protocol, uint8_t trans_id,
 			      uint32_t callref)
 {
 	struct gsm_trans *trans;
-	struct gsm_network *net = subscr->group->net;
 
 	DEBUGP(DCC, "subscr=%p, net=%p\n", subscr, net);