diff --git a/src/Ledger.h b/src/Ledger.h
index 64ae24a6d5..1f9c8b6c60 100644
--- a/src/Ledger.h
+++ b/src/Ledger.h
@@ -99,6 +99,7 @@ public:
 	void setImmutable()	{ updateHash(); mImmutable = true; }
 	bool isClosed()		{ return mClosed; }
 	bool isAccepted()	{ return mAccepted; }
+	bool isImmutable()	{ return mImmutable; }
 
 	// This ledger has closed, will never be accepted, and is accepting
 	// new transactions to be re-repocessed when do accept a new last-closed ledger
diff --git a/src/LedgerConsensus.cpp b/src/LedgerConsensus.cpp
index 1742148129..dcead92135 100644
--- a/src/LedgerConsensus.cpp
+++ b/src/LedgerConsensus.cpp
@@ -256,7 +256,7 @@ void LedgerConsensus::mapComplete(const uint256& hash, SHAMap::pointer map, bool
 
 	if (mComplete.find(hash) != mComplete.end())
 	{
-		Log(lsERROR) << "Which we already had";
+		Log(lsERROR) << "Got TXS we already had " << hash.GetHex();
 		return; // we already have this map
 	}
 
diff --git a/src/LedgerHistory.cpp b/src/LedgerHistory.cpp
index ad357139ab..f20a7ae53a 100644
--- a/src/LedgerHistory.cpp
+++ b/src/LedgerHistory.cpp
@@ -32,6 +32,7 @@ void LedgerHistory::addAcceptedLedger(Ledger::pointer ledger)
 	uint256 h(ledger->getHash());
 	boost::recursive_mutex::scoped_lock sl(mLedgersByHash.peekMutex());
 	mLedgersByHash.canonicalize(h, ledger);
+	assert(ledger && ledger->isAccepted() && ledger->isImmutable());
 	mLedgersByIndex.insert(std::make_pair(ledger->getLedgerSeq(), ledger));
 	boost::thread thread(boost::bind(&Ledger::saveAcceptedLedger, ledger));
 	thread.detach();
@@ -71,6 +72,7 @@ Ledger::pointer LedgerHistory::getLedgerByHash(const uint256& hash)
 
 Ledger::pointer LedgerHistory::canonicalizeLedger(Ledger::pointer ledger, bool save)
 {
+	assert(ledger->isImmutable());
 	uint256 h(ledger->getHash());
 
 	if (!save)
@@ -83,7 +85,7 @@ Ledger::pointer LedgerHistory::canonicalizeLedger(Ledger::pointer ledger, bool s
 	// save input ledger in map if not in map, otherwise return corresponding map ledger
 	boost::recursive_mutex::scoped_lock sl(mLedgersByHash.peekMutex());
 	mLedgersByHash.canonicalize(h, ledger);
-	if (ledger->isAccepted()) mLedgersByIndex[ledger->getLedgerSeq()]=ledger;
+	if (ledger->isAccepted()) mLedgersByIndex[ledger->getLedgerSeq()] = ledger;
 	return ledger;
 }
 // vim:ts=4
diff --git a/src/LedgerMaster.cpp b/src/LedgerMaster.cpp
index 3d1f1858c3..ea1b4bdce7 100644
--- a/src/LedgerMaster.cpp
+++ b/src/LedgerMaster.cpp
@@ -40,13 +40,14 @@ void LedgerMaster::pushLedger(Ledger::pointer newLCL, Ledger::pointer newOL)
 	assert(newLCL->isClosed() && newLCL->isAccepted());
 	assert(!newOL->isClosed() && !newOL->isAccepted());
 
-	ScopedLock sl(mLock);
-	if (mFinalizedLedger && mFinalizedLedger->isAccepted())
+	if (newLCL->isAccepted())
 	{
 		mLedgerHistory.addAcceptedLedger(mFinalizedLedger);
 		Log(lsINFO) << "StashAccepted: " << mFinalizedLedger->getHash().GetHex();
 	}
+
 	mFinalizedLedger = newLCL;
+	ScopedLock sl(mLock);
 	mCurrentLedger = newOL;
 	mEngine.setLedger(newOL);
 }