--- a/src/pixmap.cc Mon Sep 08 20:14:24 2014 +0200 +++ b/src/pixmap.cc Tue Jul 26 17:41:36 2016 +0200 @@ -31,6 +31,7 @@ #ifdef HAVE_PNG # include <png.h> +# include <zlib.h> #endif unsigned char *Pixmap::getCharData() const