diff --git a/openbsc/src/osmo-bsc_nat/bsc_ussd.c b/openbsc/src/osmo-bsc_nat/bsc_ussd.c
index 50c50ed..ff1d27a 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_ussd.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_ussd.c
@@ -318,6 +318,10 @@
 	if (!con->imsi)
 		return 0;
 
+	/* We have not verified the IMSI yet */
+	if (!con->authorized)
+		return 0;
+
 	if (!con->bsc->nat->ussd_lst_name)
 		return 0;
 	if (!con->bsc->nat->ussd_query)