diff --git a/etc/defaults/periodic.conf b/etc/defaults/periodic.conf
index 3706997a7dc2..fd0cd1a3959e 100644
--- a/etc/defaults/periodic.conf
+++ b/etc/defaults/periodic.conf
@@ -10,6 +10,9 @@
 # values set in this file.  This eases the upgrade path when defaults
 # are changed and new features are added.
 #
+# For a more detailed explanation of all the periodic.conf variables, please
+# refer to the periodic.conf(5) manual page.
+#
 # $FreeBSD$
 #