diff --git a/net/bluetooth/conn.c b/net/bluetooth/conn.c
index 046b3a7b22e..24095230eea 100644
--- a/net/bluetooth/conn.c
+++ b/net/bluetooth/conn.c
@@ -1126,6 +1126,10 @@ int bt_conn_auth_pincode_entry(struct bt_conn *conn, const char *pin)
 		return -EPERM;
 	}
 
+	if (len == 16) {
+		atomic_set_bit(conn->flags, BT_CONN_BR_LEGACY_SECURE);
+	}
+
 	return pin_code_reply(conn, pin, len);
 }
 
diff --git a/net/bluetooth/conn_internal.h b/net/bluetooth/conn_internal.h
index 05c5cc3caad..5ad2a53008b 100644
--- a/net/bluetooth/conn_internal.h
+++ b/net/bluetooth/conn_internal.h
@@ -29,6 +29,7 @@ typedef enum __packed {
 /* bt_conn flags: the flags defined here represent connection parameters */
 enum {
 	BT_CONN_AUTO_CONNECT,
+	BT_CONN_BR_LEGACY_SECURE,	/* 16 digits legacy PIN tracker */
 };
 
 struct bt_conn_le {
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 9795cdf8408..56145bbcd58 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1609,6 +1609,16 @@ static void link_key_notify(struct net_buf *buf)
 
 	if (evt->key_type == BT_LK_COMBINATION) {
 		atomic_set_bit(&conn->keys->flags, BT_KEYS_BR_LEGACY);
+
+		/*
+		 * Setting Combination Link Key as AUTHENTICATED means it was
+		 * successfully generated by 16 digits wide PIN code.
+		 */
+		if (atomic_test_and_clear_bit(conn->flags,
+					      BT_CONN_BR_LEGACY_SECURE)) {
+			atomic_set_bit(&conn->keys->flags,
+				       BT_KEYS_AUTHENTICATED);
+		}
 	}
 
 	bt_conn_unref(conn);