diff --git a/src/cpp/ripple/OrderBookDB.cpp b/src/cpp/ripple/OrderBookDB.cpp
index 4ebac57497..9bfcd25ed8 100644
--- a/src/cpp/ripple/OrderBookDB.cpp
+++ b/src/cpp/ripple/OrderBookDB.cpp
@@ -1,7 +1,9 @@
+#include "OrderBookDB.h"
+
 #include <boost/foreach.hpp>
+#include <boost/ref.hpp>
 
 #include "Application.h"
-#include "OrderBookDB.h"
 #include "Log.h"
 
 SETUP_LOG();
@@ -53,8 +55,10 @@ void OrderBookDB::setup(Ledger::ref ledger)
 				OrderBook::pointer book = boost::make_shared<OrderBook>(boost::cref(index),
 					boost::cref(ci), boost::cref(co), boost::cref(ii), boost::cref(io));
 
-				mSourceMap[currencyIssuer_ct(ci, ii)].push_back(book);
-				mDestMap[currencyIssuer_ct(co, io)].push_back(book);
+				mSourceMap[currencyIssuer_ct(boost::reference_wrapper<const uint160>(ci),
+					boost::reference_wrapper<const uint160>(ii))].push_back(book);
+				mDestMap[currencyIssuer_ct(boost::reference_wrapper<const uint160>(co),
+					boost::reference_wrapper<const uint160>(io))].push_back(book);
 			}
 		}