Index: simgear/nasal/cppbind/Ghost.hxx
--- simgear/nasal/cppbind/Ghost.hxx.orig
+++ simgear/nasal/cppbind/Ghost.hxx
@@ -32,6 +32,8 @@
 #include <boost/call_traits.hpp>
 #include <boost/mpl/has_xxx.hpp>
 
+#include <osg/Referenced>
+
 #include <map>
 #include <memory>
 
