diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index e9f4362e81e..4bde8a87996 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -668,6 +668,7 @@ device		pf			#PF OpenBSD packet-filter firewall
 device		pflog			#logging support interface for PF
 device		pfsync			#synchronization interface for PF
 device		carp			#Common Address Redundancy Protocol
+device		enc			#IPSec interface (needs FAST_IPSEC)
 device		ppp			#Point-to-point protocol
 options 	PPP_BSDCOMP		#PPP BSD-compress support
 options 	PPP_DEFLATE		#PPP zlib/deflate/gzip support