diff --git a/include/boost/phoenix/core/expression.hpp b/include/boost/phoenix/core/expression.hpp
index 2db9eec..1290c6e 100644
--- a/include/boost/phoenix/core/expression.hpp
+++ b/include/boost/phoenix/core/expression.hpp
@@ -103,7 +103,7 @@ namespace boost { namespace phoenix
             proto_grammar;
         
         static type make(BOOST_PP_REPEAT(BOOST_PHOENIX_ITERATION, M1, _))
-        {
+      { //?? actor or Actor??
             actor<base_type> const e =
                 {
                     proto::make_expr<