$OpenBSD: patch-src_Makefile_in,v 1.15 2016/04/21 23:46:47 sthen Exp $
--- src/Makefile.in.orig	Tue Apr 19 15:53:14 2016
+++ src/Makefile.in	Fri Apr 22 00:37:12 2016
@@ -532,7 +532,7 @@ include_HEADERS = rrd.h rrd_format.h rrd_client.h
 rrdcgi_SOURCES = rrd_cgi.c
 rrdcgi_LDADD = librrd.la librrdupd.la
 rrdupdate_SOURCES = rrdupdate.c
-rrdupdate_LDADD = librrdupd.la
+rrdupdate_LDADD = librrdupd.la -lpthread
 rrdtool_SOURCES = rrd_tool.c
 rrdtool_DEPENDENCIES = librrd.la
 rrdtool_LDADD = librrd.la
