diff --git a/lib/libprocstat/libprocstat.3 b/lib/libprocstat/libprocstat.3
index 3608a62cc1d5..477040ca2cf9 100644
--- a/lib/libprocstat/libprocstat.3
+++ b/lib/libprocstat/libprocstat.3
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 27, 2017
+.Dd July 29, 2017
 .Dt LIBPROCSTAT 3
 .Os
 .Sh NAME
@@ -66,6 +66,7 @@
 .Sh SYNOPSIS
 .In sys/param.h
 .In sys/queue.h
+.In sys/socket.h
 .In libprocstat.h
 .Ft void
 .Fn procstat_close "struct procstat *procstat"