$OpenBSD: patch-src_Makefile_in,v 1.18 2019/05/28 13:59:36 sthen Exp $
Index: src/Makefile.in
--- src/Makefile.in.orig
+++ src/Makefile.in
@@ -550,7 +550,7 @@ 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
