diff --git a/include/l2cap.h b/include/l2cap.h
index 4900680..478819e 100644
--- a/include/l2cap.h
+++ b/include/l2cap.h
@@ -161,6 +161,10 @@
 
 #define L2CAP_CONF_MAX_SIZE	22
 
+#define L2CAP_MODE_BASIC	0x00
+#define L2CAP_MODE_RETRANS	0x01
+#define L2CAP_MODE_FLOWCTL	0x02
+
 typedef struct {
 	uint16_t	dcid;
 	uint16_t	scid;