$OpenBSD: patch-src_imageio_format_png_c,v 1.1 2011/07/08 20:38:01 naddy Exp $
--- src/imageio/format/png.c.orig	Tue Jul  5 20:40:09 2011
+++ src/imageio/format/png.c	Tue Jul  5 20:40:23 2011
@@ -28,6 +28,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <png.h>
+#include <zlib.h>
 #include <inttypes.h>
 
 DT_MODULE(1)
