diff --git a/monitor/bt.h b/monitor/bt.h
index c4eeb02..38d11d5 100644
--- a/monitor/bt.h
+++ b/monitor/bt.h
@@ -2230,6 +2230,7 @@ struct bt_hci_evt_le_long_term_key_request {
 #define BT_HCI_ERR_UNKNOWN_CONN_ID		0x02
 #define BT_HCI_ERR_HARDWARE_FAILURE		0x03
 #define BT_HCI_ERR_PAGE_TIMEOUT			0x04
+#define BT_HCI_ERR_PIN_OR_KEY_MISSING		0x06
 #define BT_HCI_ERR_MEM_CAPACITY_EXCEEDED	0x07
 #define BT_HCI_ERR_COMMAND_DISALLOWED		0x0c
 #define BT_HCI_ERR_UNSUPPORTED_FEATURE		0x11