diff --git a/src/ripple_app/ledger/OrderBookDB.cpp b/src/ripple_app/ledger/OrderBookDB.cpp
index bc82942bee..d5fdbe67c8 100644
--- a/src/ripple_app/ledger/OrderBookDB.cpp
+++ b/src/ripple_app/ledger/OrderBookDB.cpp
@@ -210,6 +210,7 @@ BookListeners::pointer OrderBookDB::makeBookListeners (RippleCurrency const& cur
         mListeners [RippleBookRef (
             RippleAssetRef (currencyPays, issuerPays),
             RippleAssetRef (currencyGets, issuerGets))] = ret;
+        assert (getBookListeners (currencyPays, currencyGets, issuerPays, issuerGets) == ret);
     }
 
     return ret;
@@ -228,12 +229,12 @@ BookListeners::pointer OrderBookDB::getBookListeners (RippleCurrency const& curr
     if (it0 != mListeners.end ())
         ret = it0->second;
 
-    return ret;;
+    return ret;
 }
 
 // Based on the meta, send the meta to the streams that are listening
 // We need to determine which streams a given meta effects
-void OrderBookDB::processTxn (Ledger::ref ledger, const AcceptedLedgerTx& alTx, Json::Value& jvObj)
+void OrderBookDB::processTxn (Ledger::ref ledger, const AcceptedLedgerTx& alTx, Json::Value const& jvObj)
 {
     ScopedLockType sl (mLock, __FILE__, __LINE__);
 
@@ -249,6 +250,7 @@ void OrderBookDB::processTxn (Ledger::ref ledger, const AcceptedLedgerTx& alTx,
                 {
                     SField* field = NULL;
 
+                    // We need a field that contains the TakerGets and TakerPays parameters
                     if (node.getFName () == sfModifiedNode)
                     {
                         field = &sfPreviousFields;
@@ -313,7 +315,7 @@ void BookListeners::removeSubscriber (uint64 seq)
     mListeners.erase (seq);
 }
 
-void BookListeners::publish (Json::Value& jvObj)
+void BookListeners::publish (Json::Value const& jvObj)
 {
     Json::FastWriter jfwWriter;
     std::string sObj = jfwWriter.write (jvObj);
diff --git a/src/ripple_app/ledger/OrderBookDB.h b/src/ripple_app/ledger/OrderBookDB.h
index cdf71eea11..f88b500508 100644
--- a/src/ripple_app/ledger/OrderBookDB.h
+++ b/src/ripple_app/ledger/OrderBookDB.h
@@ -29,7 +29,7 @@ public:
     BookListeners ();
     void addSubscriber (InfoSub::ref sub);
     void removeSubscriber (uint64 sub);
-    void publish (Json::Value& jvObj);
+    void publish (Json::Value const& jvObj);
 
 private:
     typedef RippleRecursiveMutex LockType;
@@ -73,7 +73,7 @@ public:
             RippleIssuer const& issuerPays, RippleIssuer const& issuerGets);
 
     // see if this txn effects any orderbook
-    void processTxn (Ledger::ref ledger, const AcceptedLedgerTx& alTx, Json::Value& jvObj);
+    void processTxn (Ledger::ref ledger, const AcceptedLedgerTx& alTx, Json::Value const& jvObj);
 
 private:
     // by ci/ii
diff --git a/src/ripple_app/misc/NetworkOPs.cpp b/src/ripple_app/misc/NetworkOPs.cpp
index 9f5f49c98b..d505c09763 100644
--- a/src/ripple_app/misc/NetworkOPs.cpp
+++ b/src/ripple_app/misc/NetworkOPs.cpp
@@ -2609,6 +2609,7 @@ bool NetworkOPsImp::subBook (InfoSub::ref isrListener, RippleCurrency const& cur
     BookListeners::pointer listeners =
         getApp().getOrderBookDB ().makeBookListeners (currencyPays, currencyGets, issuerPays, issuerGets);
 
+    assert (listeners);
     if (listeners)
         listeners->addSubscriber (isrListener);
 
diff --git a/src/ripple_app/rpc/RPCHandler.cpp b/src/ripple_app/rpc/RPCHandler.cpp
index b664f78f9b..f01dbbc6bb 100644
--- a/src/ripple_app/rpc/RPCHandler.cpp
+++ b/src/ripple_app/rpc/RPCHandler.cpp
@@ -3530,10 +3530,10 @@ Json::Value RPCHandler::doSubscribe (Json::Value params, Resource::Charge& loadT
                     || !jvSubRequest["taker_gets"].isObject ())
                 return rpcError (rpcINVALID_PARAMS);
 
-            uint160         uTakerPaysCurrencyID;
-            uint160         uTakerPaysIssuerID;
-            uint160         uTakerGetsCurrencyID;
-            uint160         uTakerGetsIssuerID;
+            RippleCurrency  uTakerPaysCurrencyID;
+            RippleIssuer    uTakerPaysIssuerID;
+            RippleCurrency  uTakerGetsCurrencyID;
+            RippleIssuer    uTakerGetsIssuerID;
             bool            bBoth           = (jvSubRequest.isMember ("both") && jvSubRequest["both"].asBool ())
                                               || (jvSubRequest.isMember ("both_sides") && jvSubRequest["both_sides"].asBool ());  // DEPRECATED
             bool            bSnapshot       = (jvSubRequest.isMember ("snapshot") && jvSubRequest["snapshot"].asBool ())