--- qwtplot3d/src/qwt3d_function.cpp	2004-06-10 02:57:38.000000000 +1000
+++ qwtplot3d-patched/src/qwt3d_function.cpp	2015-05-03 14:08:23.209731926 +1000
@@ -1,5 +1,6 @@
 #include "qwt3d_surfaceplot.h"
 #include "qwt3d_function.h"
+#include <stdio.h>
 
 using namespace Qwt3D;
 
