--- a/3rdparty/qwtplot3d/src/qwt3d_function.cpp	2009-07-25 20:03:28.000000000 -0700
+++ b/3rdparty/qwtplot3d/src/qwt3d_function.cpp	2009-07-25 20:03:28.000000000 -0700
@@ -1,5 +1,6 @@
 #include "qwt3d_surfaceplot.h"
 #include "qwt3d_function.h"
+#include <cstdio>
 
 using namespace Qwt3D;