diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index a531620ede5..47d6bcb4e5d 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -977,6 +977,9 @@ device		lagg
 # WireGuard interface.
 device		wg
 
+# dummymbuf – mbuf alteration pfil hooks
+device		dummymbuf
+
 #
 # Internet family options:
 #