diff --git a/lib/hci.h b/lib/hci.h
index e1feba7..1ea084a 100644
--- a/lib/hci.h
+++ b/lib/hci.h
@@ -2287,6 +2287,7 @@ struct sockaddr_hci {
 
 #define HCI_CHANNEL_RAW		0
 #define HCI_CHANNEL_CONTROL	1
+#define HCI_CHANNEL_MONITOR	2
 
 struct hci_filter {
 	uint32_t type_mask;