diff --git a/src/session_impl.cpp b/src/session_impl.cpp
index 78d2586de..c61d3b696 100644
--- a/src/session_impl.cpp
+++ b/src/session_impl.cpp
@@ -323,6 +323,7 @@ namespace aux {
 		TORRENT_SETTING(boolean, upnp_ignore_nonrouters)
  		TORRENT_SETTING(integer, send_buffer_low_watermark)
  		TORRENT_SETTING(integer, send_buffer_watermark)
+		TORRENT_SETTING(integer, send_buffer_watermark_factor)
 #ifndef TORRENT_NO_DEPRECATE
 		TORRENT_SETTING(boolean, auto_upload_slots)
 		TORRENT_SETTING(boolean, auto_upload_slots_rate_based)