diff --git a/etk/boost_to_std/etk/functional.h b/etk/boost_to_std/etk/functional.h
index 9db78fa..1eb7da1 100644
--- a/etk/boost_to_std/etk/functional.h
+++ b/etk/boost_to_std/etk/functional.h
@@ -6,5 +6,18 @@
 #include <boost/bind.hpp>
 #include <boost/bind/placeholders.hpp>
 
+namespace boost {
+	namespace placeholders {
+		boost::arg<1> _1;
+		boost::arg<2> _2;
+		boost::arg<3> _3;
+		boost::arg<4> _4;
+		boost::arg<5> _5;
+		boost::arg<6> _6;
+		boost::arg<7> _7;
+		boost::arg<8> _8;
+		boost::arg<9> _9;
+	}
+}
 
 #endif