diff --git a/include/osg/GraphicsContext b/include/osg/GraphicsContext
index 33d7b0b12..ac196d5a8 100644
--- a/include/osg/GraphicsContext
+++ b/include/osg/GraphicsContext
@@ -597,10 +597,6 @@ struct WindowingSystemInterfaceProxy
     osg::ref_ptr<T> _wsi;
 };
 
-#define REGISTER_WINDOWINGSYSTEMINTERFACE(ext, classname) \
-    extern "C" void graphicswindow_##ext(void) {} \
-    static osg::WindowingSystemInterfaceProxy<classname> s_proxy_##classname(#ext);
-
 }
 
 #endif
diff --git a/include/osgViewer/GraphicsWindow b/include/osgViewer/GraphicsWindow
index 9757f8f02..2ee2f24c0 100644
--- a/include/osgViewer/GraphicsWindow
+++ b/include/osgViewer/GraphicsWindow
@@ -273,6 +273,11 @@ class GraphicsWindowEmbedded : public GraphicsWindow
         virtual void raiseWindow() {}
 };
 
+
+#define REGISTER_WINDOWINGSYSTEMINTERFACE(ext, classname) \
+    extern "C" OSGVIEWER_EXPORT void graphicswindow_##ext(void) {} \
+    static osg::WindowingSystemInterfaceProxy<classname> s_proxy_##classname(#ext);
+
 struct GraphicsWindowFunctionProxy
 {
     GraphicsWindowFunctionProxy(CGraphicsWindowFunction function) { (function)(); }