diff --git a/src/db.h b/src/db.h
index 0f1d40d6..68d7a63c 100644
--- a/src/db.h
+++ b/src/db.h
@@ -69,7 +69,7 @@ int db_update_sqn(struct db_context *dbc, int64_t id,
 int db_get_auc(struct db_context *dbc, const char *imsi,
 	       unsigned int auc_3g_ind, struct osmo_auth_vector *vec,
 	       unsigned int num_vec, const uint8_t *rand_auts,
-	       const uint8_t *auts);
+	       const uint8_t *auts, bool separation_bit);
 
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/gsm/protocol/gsm_23_003.h>
diff --git a/src/db_auc.c b/src/db_auc.c
index 2cf71438..6eaee9d6 100644
--- a/src/db_auc.c
+++ b/src/db_auc.c
@@ -189,7 +189,7 @@ out:
 int db_get_auc(struct db_context *dbc, const char *imsi,
 	       unsigned int auc_3g_ind, struct osmo_auth_vector *vec,
 	       unsigned int num_vec, const uint8_t *rand_auts,
-	       const uint8_t *auts)
+	       const uint8_t *auts, bool separation_bit)
 {
 	struct osmo_sub_auth_data aud2g, aud3g;
 	int64_t subscr_id;
@@ -209,6 +209,12 @@ int db_get_auc(struct db_context *dbc, const char *imsi,
 		       aud3g.u.umts.ind_bitlen, aud3g.u.umts.ind);
 		aud3g.u.umts.ind &= (1U << aud3g.u.umts.ind_bitlen) - 1;
 	}
+	/* the first bit (bit0) cannot be used as AMF anymore, but has been
+	 * re-appropriated as the separation bit.  See 3GPP TS 33.102 Annex H
+	 * together with 3GPP TS 33.401 / 33.402 / 33.501 */
+	aud3g.u.umts.amf[0] = aud3g.u.umts.amf[0] & 0x7f;
+	if (separation_bit)
+		aud3g.u.umts.amf[0] |= 0x80;
 
 	LOGAUC(imsi, LOGL_DEBUG, "Calling to generate %u vectors\n", num_vec);
 	rc = auc_compute_vectors(vec, num_vec, &aud2g, &aud3g, rand_auts, auts);
diff --git a/src/hlr.c b/src/hlr.c
index 76b2f221..87f92e39 100644
--- a/src/hlr.c
+++ b/src/hlr.c
@@ -233,6 +233,7 @@ static int rx_send_auth_info(struct osmo_gsup_conn *conn,
 {
 	struct osmo_gsup_message gsup_out;
 	struct msgb *msg_out;
+	bool separation_bit = false;
 	int rc;
 
 	subscr_create_on_demand(gsup->imsi);
@@ -241,10 +242,13 @@ static int rx_send_auth_info(struct osmo_gsup_conn *conn,
 	memset(&gsup_out, 0, sizeof(gsup_out));
 	memcpy(&gsup_out.imsi, &gsup->imsi, sizeof(gsup_out.imsi));
 
+	if (gsup->rat_types_len >= 1 && gsup->rat_types[0] == OSMO_RAT_EUTRAN_SGS)
+		separation_bit = true;
+
 	rc = db_get_auc(dbc, gsup->imsi, conn->auc_3g_ind,
 			gsup_out.auth_vectors,
 			ARRAY_SIZE(gsup_out.auth_vectors),
-			gsup->rand, gsup->auts);
+			gsup->rand, gsup->auts, separation_bit);
 	if (rc <= 0) {
 		gsup_out.message_type = OSMO_GSUP_MSGT_SEND_AUTH_INFO_ERROR;
 		switch (rc) {
diff --git a/src/hlr_vty_subscr.c b/src/hlr_vty_subscr.c
index 8c3ef2b7..f7089c4c 100644
--- a/src/hlr_vty_subscr.c
+++ b/src/hlr_vty_subscr.c
@@ -628,7 +628,7 @@ DEFUN(subscriber_rat,
 	const char *id = argv[1];
 	const char *rat_str = argv[2];
 	const char *allowed_forbidden = argv[3];
-	enum osmo_rat_type rat;
+	enum osmo_rat_type rat = OSMO_RAT_UNKNOWN;
 	bool allowed;
 	int rc;
 
@@ -636,6 +636,8 @@ DEFUN(subscriber_rat,
 		rat = OSMO_RAT_GERAN_A;
 	else if (strcmp(rat_str, "utran-iu") == 0)
 		rat = OSMO_RAT_UTRAN_IU;
+	else if (strcmp(rat_str, "eutran") == 0)
+		rat = OSMO_RAT_EUTRAN_SGS;
 
 	allowed = (strcmp(allowed_forbidden, "allowed") == 0);