$OpenBSD: patch-Makefile,v 1.2 2012/05/20 16:44:53 naddy Exp $
--- Makefile.orig	Fri May 18 00:33:00 2012
+++ Makefile	Fri May 18 00:33:54 2012
@@ -38,7 +38,7 @@ ifeq ($(UNAME), FreeBSD)
 CFLAGS+= -DHAVE_FFLAGS
 endif
 ifeq ($(UNAME), OpenBSD)
-CFLAGS+= -DHAVE_FFLAGS
+CFLAGS+= -DHAVE_FFLAGS -pthread
 WARNS+=  -Wno-system-headers
 endif
 ifeq ($(UNAME), NetBSD)
@@ -48,9 +48,15 @@ ifeq ($(UNAME), DragonFlyBSD)
 CFLAGS+= -DHAVE_FFLAGS
 endif
 
-CFLAGS+= -O -pipe -I$(PREFIX)/include $(WARNS)
+CFLAGS+= -I$(PREFIX)/include $(WARNS)
 
-LDFLAGS= -L$(PREFIX)/lib -lz -lpthread
+LDFLAGS= -L$(PREFIX)/lib -lz
+
+ifeq ($(UNAME), OpenBSD)
+LDFLAGS+= -pthread
+else
+LDFLAGS+= -lpthread
+endif
 
 ifeq ($(UNAME), FreeBSD)
 LDFLAGS+= -lmd
