diff -Naur OpenImageIO-oiio-1c4030e.orig/src/ico.imageio/icooutput.cpp OpenImageIO-oiio-1c4030e/src/ico.imageio/icooutput.cpp
--- OpenImageIO-oiio-1c4030e.orig/src/ico.imageio/icooutput.cpp	2011-08-06 12:56:10.000000000 -0500
+++ OpenImageIO-oiio-1c4030e/src/ico.imageio/icooutput.cpp	2011-11-05 14:29:27.850429691 -0500
@@ -31,6 +31,7 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cmath>
+#include <zlib.h>
 
 #include "ico.h"
 #include "../png.imageio/png_pvt.h"