--- extremetuxracer-0.4.orig/src/ppgltk/images/png_reader.cpp
+++ extremetuxracer-0.4/src/ppgltk/images/png_reader.cpp
@@ -19,6 +19,11 @@
 
 #include "png_reader.h"
 
+#if PNG_LIBPNG_VER_MAJOR >= 1 && PNG_LIBPNG_VER_MINOR >= 4
+#define int_p_NULL NULL
+#define png_infopp_NULL NULL
+#endif
+
 namespace pp {
 
 ReaderPNG::ReaderPNG(const char *fileName)