diff --git a/Fltk/graphicWindow.cpp b/Fltk/graphicWindow.cpp
index 98efe2bdfd6a5f8f352269a8e887b96a1d596675..d7cd48b0d98f3d1e90e8f951c10d4e89331da3d7 100644
--- a/Fltk/graphicWindow.cpp
+++ b/Fltk/graphicWindow.cpp
@@ -14,6 +14,7 @@ typedef unsigned long intptr_t;
 #include <stdlib.h>
 #include <stdio.h>
 #include <time.h>
+#include <fstream>
 #include <FL/Fl_Box.H>
 #include <FL/fl_ask.H>
 #include <FL/filename.H>