$OpenBSD: patch-src_imageio_format_png_c,v 1.2 2011/12/09 20:11:00 sthen Exp $
--- src/imageio/format/png.c.orig	Mon Nov  7 06:46:13 2011
+++ src/imageio/format/png.c	Fri Dec  9 15:54:31 2011
@@ -27,6 +27,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <png.h>
+#include <zlib.h>
 #include <inttypes.h>
 #include <zlib.h>
 
