diff -pruN extreme-tuxracer-0.5beta.orig/src/ppgltk/images/png_reader.h extreme-tuxracer-0.5beta/src/ppgltk/images/png_reader.h
--- extreme-tuxracer-0.5beta.orig/src/ppgltk/images/png_reader.h	2011-05-12 14:27:02.647999007 +0000
+++ extreme-tuxracer-0.5beta/src/ppgltk/images/png_reader.h	2011-05-12 14:30:52.270998929 +0000
@@ -19,6 +19,9 @@
 #ifndef _PNG_READER_H
 #define _PNG_READER_H
 
+#define png_infopp_NULL (png_infopp)NULL
+#define int_p_NULL (int*)NULL
+
 #include "image.h"
 
 #include <png.h>