Index: configure.ac
--- configure.ac.orig
+++ configure.ac
@@ -145,7 +145,7 @@
 
 # Set some O/S specific stuff
 case `uname -s` in
-    Darwin|FreeBSD)
+    Darwin|FreeBSD|OpenBSD)
         AC_CHECK_LIB(pthread, pthread_create,,
             [AC_MSG_ERROR([required library libpthread missing])])
         ;;
