Add constant for Bluetooth socket options level
diff --git a/include/bluetooth.h b/include/bluetooth.h
index 1d37778..d483d90 100644
--- a/include/bluetooth.h
+++ b/include/bluetooth.h
@@ -41,6 +41,10 @@
 #define PF_BLUETOOTH	AF_BLUETOOTH
 #endif
 
+#ifndef SOL_BLUETOOTH
+#define SOL_BLUETOOTH	274
+#endif
+
 #define BTPROTO_L2CAP	0
 #define BTPROTO_HCI	1
 #define BTPROTO_SCO	2