diff --git a/examples/osgslice/osgslice.cpp b/examples/osgslice/osgslice.cpp
index e6c393df3..e031eeb60 100644
--- a/examples/osgslice/osgslice.cpp
+++ b/examples/osgslice/osgslice.cpp
@@ -26,11 +26,16 @@
 #include <osgDB/ReadFile>
 #include <osgDB/WriteFile>
 
+#include <osgViewer/GraphicsWindow>
+
 #include <sstream>
 #include <iostream>
 
 #define MIN_NEARFAROFFSET 0.1
 
+// force the WIndowingSystem to initialize to allow us to create a graphics context.
+USE_GRAPHICSWINDOW()
+
 class SliceProcessor
 {
     public: