diff -up allegro-5.0.3/addons/image/png.c.fix allegro-5.0.3/addons/image/png.c
--- allegro-5.0.3/addons/image/png.c.fix 2011-12-09 14:41:00.820972675 -0500
+++ allegro-5.0.3/addons/image/png.c 2011-12-09 14:41:08.491898729 -0500
@@ -4,6 +4,7 @@
#include <png.h>
+#include <zlib.h>
#include "allegro5/allegro.h"
#include "allegro5/allegro_image.h"