diff --git a/include/boost/python/class.hpp b/include/boost/python/class.hpp
index 16bef205..ac453c58 100644
--- a/include/boost/python/class.hpp
+++ b/include/boost/python/class.hpp
@@ -59,7 +59,7 @@
 
 namespace boost { namespace python {
 
-template <class DerivedVisitor> struct def_visitor;
+template <class DerivedVisitor> class def_visitor;
 
 enum no_init_t { no_init };