diff --git a/include/libtorrent/deadline_timer.hpp b/include/libtorrent/deadline_timer.hpp
index a57597eef..4f0ca2cbe 100644
--- a/include/libtorrent/deadline_timer.hpp
+++ b/include/libtorrent/deadline_timer.hpp
@@ -52,6 +52,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/time.hpp"
 
 // asio time_traits
+#if !TORRENT_USE_BOOST_DATE_TIME
 #if BOOST_VERSION >= 103500
 namespace boost { 
 #endif
@@ -78,6 +79,7 @@ namespace asio
 #if BOOST_VERSION >= 103500
 }
 #endif
+#endif
 
 namespace libtorrent
 {