diff --git a/lib/libcasper/libcasper/libcasper.3 b/lib/libcasper/libcasper/libcasper.3
index 896674d6f71..9b99a7cc2a7 100644
--- a/lib/libcasper/libcasper/libcasper.3
+++ b/lib/libcasper/libcasper/libcasper.3
@@ -27,7 +27,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd January 3, 2018
+.Dd February 5, 2018
 .Dt LIBCASPER 3
 .Os
 .Sh NAME
@@ -47,6 +47,7 @@
 .Sh LIBRARY
 .Lb libcasper
 .Sh SYNOPSIS
+.Fd #define WITH_CASPER
 .In sys/nv.h
 .In libcasper.h
 .Ft "cap_channel_t *"