diff --git a/openbsc/src/gsm_subscriber.c b/openbsc/src/gsm_subscriber.c
index 84e14a0..a4e35c7 100644
--- a/openbsc/src/gsm_subscriber.c
+++ b/openbsc/src/gsm_subscriber.c
@@ -35,17 +35,19 @@
 extern struct llist_head *subscr_bsc_active_subscriber(void);
 
 struct gsm_subscriber *subscr_get_by_tmsi(struct gsm_network *net,
-					  const char *tmsi)
+					  u_int32_t tmsi)
 {
+	char tmsi_string[14];
 	struct gsm_subscriber *subscr;
 
 	/* we might have a record in memory already */
 	llist_for_each_entry(subscr, subscr_bsc_active_subscriber(), entry) {
-		if (strcmp(subscr->tmsi, tmsi) == 0)
+		if (tmsi == subscr->tmsi)
 			return subscr_get(subscr);
 	}
 
-	return db_get_subscriber(net, GSM_SUBSCRIBER_TMSI, tmsi);
+	sprintf(tmsi_string, "%u", tmsi);
+	return db_get_subscriber(net, GSM_SUBSCRIBER_TMSI, tmsi_string);
 }
 
 struct gsm_subscriber *subscr_get_by_imsi(struct gsm_network *net,