diff --git a/src/ast_handlers.hpp b/src/ast_handlers.hpp
index 540d7e2..5b5a152 100644
--- a/src/ast_handlers.hpp
+++ b/src/ast_handlers.hpp
@@ -409,13 +409,11 @@
     }
 };
 
-struct commandNamesVisitor {
-    template <typename T>
-    std::string operator()(boost::type<T>)
-    {
-        return T::name;
-    }
-};
+template <typename T>
+std::string commandNamesVisitor (boost::type<T>)
+{
+    return T::name;
+}
 
 struct createCommandSuggestions_class {
     template <typename T, typename Iterator, typename Context>
@@ -426,7 +424,7 @@
 
         parserContext.m_suggestions.clear();
         boost::mpl::for_each<CommandTypes, boost::type<boost::mpl::_>>([&parserContext](auto cmd) {
-            parserContext.m_suggestions.insert({commandNamesVisitor()(cmd), " "});
+            parserContext.m_suggestions.insert({commandNamesVisitor(cmd), " "});
         });
     }
 };
diff --git a/src/grammars.hpp b/src/grammars.hpp
index 02d6666..253a16a 100644
--- a/src/grammars.hpp
+++ b/src/grammars.hpp
@@ -74,7 +74,7 @@
     command_names_table()
     {
         boost::mpl::for_each<CommandTypes, boost::type<boost::mpl::_>>([this](auto cmd) {
-            add(commandNamesVisitor()(cmd), decltype(help_::m_cmd)(cmd));
+            add(commandNamesVisitor(cmd), decltype(help_::m_cmd)(cmd));
         });
     }
 } const command_names;