diff --git a/include/openbsc/db.h b/include/openbsc/db.h
index d102dfe..e02bb62 100644
--- a/include/openbsc/db.h
+++ b/include/openbsc/db.h
@@ -32,5 +32,6 @@
 int db_get_subscriber(enum gsm_subscriber_field field, struct gsm_subscriber* subscriber);
 int db_set_subscriber(struct gsm_subscriber* subscriber);
 int db_subscriber_alloc_tmsi(struct gsm_subscriber* subscriber);
+int db_subscriber_assoc_imei(struct gsm_subscriber* subscriber, char imei[GSM_IMEI_LENGTH]);
 
 #endif /* _DB_H */
diff --git a/include/openbsc/gsm_subscriber.h b/include/openbsc/gsm_subscriber.h
index 03333d4..0eb3654 100644
--- a/include/openbsc/gsm_subscriber.h
+++ b/include/openbsc/gsm_subscriber.h
@@ -4,11 +4,13 @@
 #include <sys/types.h>
 #include "gsm_data.h"
 
+#define GSM_IMEI_LENGTH 17
 #define GSM_IMSI_LENGTH 17
 #define GSM_TMSI_LENGTH 17
 #define GSM_NAME_LENGTH 128
 
 struct gsm_subscriber {
+	u_int64_t id;
 	char imsi[GSM_IMSI_LENGTH];
 	char tmsi[GSM_TMSI_LENGTH];
 	u_int16_t lac;