diff --git a/libethereum/EthereumHost.cpp b/libethereum/EthereumHost.cpp
index 55a1d1bf0..23089896d 100644
--- a/libethereum/EthereumHost.cpp
+++ b/libethereum/EthereumHost.cpp
@@ -41,6 +41,7 @@ using namespace dev::eth;
 using namespace p2p;
 
 unsigned const EthereumHost::c_oldProtocolVersion = 60; //TODO: remove this once v61+ is common
+static unsigned const c_maxSendTransactions = 256;
 
 char const* const EthereumHost::s_stateNames[static_cast<int>(SyncState::Size)] = {"Idle", "Waiting", "Hashes", "Blocks", "NewBlocks" };
 
@@ -67,8 +68,7 @@ bool EthereumHost::ensureInitialised()
 		m_latestBlockSent = m_chain.currentHash();
 		clog(NetNote) << "Initialising: latest=" << m_latestBlockSent;
 
-		for (auto const& i: m_tq.transactions())
-			m_transactionsSent.insert(i.first);
+		m_transactionsSent = m_tq.knownTransactions();
 		return true;
 	}
 	return false;
@@ -114,25 +114,26 @@ void EthereumHost::doWork()
 void EthereumHost::maintainTransactions()
 {
 	// Send any new transactions.
-	unordered_map<std::shared_ptr<EthereumPeer>, h256s> peerTransactions;
-	auto ts = m_tq.transactions();
-	for (auto const& i: ts)
+	unordered_map<std::shared_ptr<EthereumPeer>, std::vector<size_t>> peerTransactions;
+	auto ts = m_tq.topTransactions(c_maxSendTransactions);
+	for (size_t i = 0; i < ts.size(); ++i)
 	{
-		bool unsent = !m_transactionsSent.count(i.first);
-		auto peers = get<1>(randomSelection(0, [&](EthereumPeer* p) { return p->m_requireTransactions || (unsent && !p->m_knownTransactions.count(i.first)); }));
+		auto const& t = ts[i];
+		bool unsent = !m_transactionsSent.count(t.sha3());
+		auto peers = get<1>(randomSelection(0, [&](EthereumPeer* p) { return p->m_requireTransactions || (unsent && !p->m_knownTransactions.count(t.sha3())); }));
 		for (auto const& p: peers)
-			peerTransactions[p].push_back(i.first);
+			peerTransactions[p].push_back(i);
 	}
 	for (auto const& t: ts)
-		m_transactionsSent.insert(t.first);
+		m_transactionsSent.insert(t.sha3());
 	foreachPeer([&](shared_ptr<EthereumPeer> _p)
 	{
 		bytes b;
 		unsigned n = 0;
-		for (auto const& h: peerTransactions[_p])
+		for (auto const& i: peerTransactions[_p])
 		{
-			_p->m_knownTransactions.insert(h);
-			b += ts[h].rlp();
+			_p->m_knownTransactions.insert(ts[i].sha3());
+			b += ts[i].rlp();
 			++n;
 		}
 
diff --git a/libethereum/State.cpp b/libethereum/State.cpp
index a000d628a..5362f6f68 100644
--- a/libethereum/State.cpp
+++ b/libethereum/State.cpp
@@ -47,6 +47,7 @@ namespace fs = boost::filesystem;
 #define ETH_TIMED_ENACTMENTS 0
 
 static const u256 c_blockReward = c_network == Network::Olympic ? (1500 * finney) : (5 * ether);
+static const unsigned c_maxSyncTransactions = 256;
 
 const char* StateSafeExceptions::name() { return EthViolet "⚙" EthBlue " ℹ"; }
 const char* StateDetail::name() { return EthViolet "⚙" EthWhite " ◌"; }
@@ -495,7 +496,7 @@ pair<TransactionReceipts, bool> State::sync(BlockChain const& _bc, TransactionQu
 	pair<TransactionReceipts, bool> ret;
 	ret.second = false;
 
-	auto ts = _tq.transactions();
+	auto ts = _tq.topTransactions(c_maxSyncTransactions);
 
 	LastHashes lh;
 
@@ -504,27 +505,26 @@ pair<TransactionReceipts, bool> State::sync(BlockChain const& _bc, TransactionQu
 	for (int goodTxs = 1; goodTxs; )
 	{
 		goodTxs = 0;
-		for (auto const& i: ts)
-			if (!m_transactionSet.count(i.first))
+		for (auto const& t: ts)
+			if (!m_transactionSet.count(t.sha3()))
 			{
 				try
 				{
-					if (i.second.gasPrice() >= _gp.ask(*this))
+					if (t.gasPrice() >= _gp.ask(*this))
 					{
 	//					Timer t;
 						if (lh.empty())
 							lh = _bc.lastHashes();
-						execute(lh, i.second);
+						execute(lh, t);
 						ret.first.push_back(m_receipts.back());
-						_tq.noteGood(i);
 						++goodTxs;
 	//					cnote << "TX took:" << t.elapsed() * 1000;
 					}
-					else if (i.second.gasPrice() < _gp.ask(*this) * 9 / 10)
+					else if (t.gasPrice() < _gp.ask(*this) * 9 / 10)
 					{
 						// less than 90% of our ask price for gas. drop.
-						cnote << i.first << "Dropping El Cheapo transaction (<90% of ask price)";
-						_tq.drop(i.first);
+						cnote << t.sha3() << "Dropping El Cheapo transaction (<90% of ask price)";
+						_tq.drop(t.sha3());
 					}
 				}
 				catch (InvalidNonce const& in)
@@ -535,57 +535,54 @@ pair<TransactionReceipts, bool> State::sync(BlockChain const& _bc, TransactionQu
 					if (req > got)
 					{
 						// too old
-						for (Transaction const& t: m_transactions)
-							if (t.from() == i.second.from())
+						for (Transaction const& mt: m_transactions)
+						{
+							if (mt.from() == t.from())
 							{
-								if (t.nonce() < i.second.nonce())
-								{
-									cnote << i.first << "Dropping old transaction (nonce too low)";
-									_tq.drop(i.first);
-								}
-								else if (t.nonce() == i.second.nonce() && t.gasPrice() <= i.second.gasPrice())
-								{
-									cnote << i.first << "Dropping old transaction (gas price lower)";
-									_tq.drop(i.first);
-								}
+								if (mt.nonce() < t.nonce())
+									cnote << t.sha3() << "Dropping old transaction (nonce too low)";
+								else if (mt.nonce() == t.nonce() && mt.gasPrice() <= t.gasPrice())
+									cnote << t.sha3() << "Dropping old transaction (gas price lower)";
 							}
+						}
+						_tq.drop(t.sha3());
 					}
-					else if (got > req + _tq.waiting(i.second.sender()))
+					else if (got > req + _tq.waiting(t.sender()))
 					{
 						// too new
-						cnote << i.first << "Dropping new transaction (too many nonces ahead)";
-						_tq.drop(i.first);
+						cnote << t.sha3() << "Dropping new transaction (too many nonces ahead)";
+						_tq.drop(t.sha3());
 					}
 					else
-						_tq.setFuture(i);
+						_tq.setFuture(t.sha3());
 				}
 				catch (BlockGasLimitReached const& e)
 				{
 					bigint const& got = *boost::get_error_info<errinfo_got>(e);
 					if (got > m_currentBlock.gasLimit)
 					{
-						cnote << i.first << "Dropping over-gassy transaction (gas > block's gas limit)";
-						_tq.drop(i.first);
+						cnote << t.sha3() << "Dropping over-gassy transaction (gas > block's gas limit)";
+						_tq.drop(t.sha3());
 					}
 					else
 					{
 						// Temporarily no gas left in current block.
 						// OPTIMISE: could note this and then we don't evaluate until a block that does have the gas left.
 						// for now, just leave alone.
-//						_tq.setFuture(i);
+//						_tq.setFuture(t.sha3());
 					}
 				}
 				catch (Exception const& _e)
 				{
 					// Something else went wrong - drop it.
-					cnote << i.first << "Dropping invalid transaction:" << diagnostic_information(_e);
-					_tq.drop(i.first);
+					cnote << t.sha3() << "Dropping invalid transaction:" << diagnostic_information(_e);
+					_tq.drop(t.sha3());
 				}
 				catch (std::exception const&)
 				{
 					// Something else went wrong - drop it.
-					_tq.drop(i.first);
-					cnote << i.first << "Transaction caused low-level exception :(";
+					_tq.drop(t.sha3());
+					cnote << t.sha3() << "Transaction caused low-level exception :(";
 				}
 			}
 		if (chrono::steady_clock::now() > deadline)
diff --git a/libethereum/TransactionQueue.cpp b/libethereum/TransactionQueue.cpp
index d2ced467e..478b4ff3c 100644
--- a/libethereum/TransactionQueue.cpp
+++ b/libethereum/TransactionQueue.cpp
@@ -95,10 +95,20 @@ ImportResult TransactionQueue::import(Transaction const& _transaction, ImportCal
 	return ret;
 }
 
-std::unordered_map<h256, Transaction> TransactionQueue::transactions() const
+Transactions TransactionQueue::topTransactions(unsigned _limit) const
 {
 	ReadGuard l(m_lock);
-	return m_current;
+	Transactions res;
+	unsigned n = _limit;
+	for (auto t = m_current.begin(); n != 0 && t != m_current.end(); ++t, --n)
+		res.push_back(t->transaction);
+	return res;
+}
+
+h256Hash TransactionQueue::knownTransactions() const
+{
+	ReadGuard l(m_lock);
+	return m_known;
 }
 
 ImportResult TransactionQueue::manageImport_WITH_LOCK(h256 const& _h, Transaction const& _transaction, ImportCallback const& _cb)
@@ -108,35 +118,50 @@ ImportResult TransactionQueue::manageImport_WITH_LOCK(h256 const& _h, Transactio
 		// Check validity of _transactionRLP as a transaction. To do this we just deserialise and attempt to determine the sender.
 		// If it doesn't work, the signature is bad.
 		// The transaction's nonce may yet be invalid (or, it could be "valid" but we may be missing a marginally older transaction).
+		assert(_h == _transaction.sha3());
 
 		// Remove any prior transaction with the same nonce but a lower gas price.
 		// Bomb out if there's a prior transaction with higher gas price.
-		auto r = m_senders.equal_range(_transaction.from());
-		for (auto it = r.first; it != r.second; ++it)
-			if (m_current.count(it->second) && m_current[it->second].nonce() == _transaction.nonce())
-				if (_transaction.gasPrice() < m_current[it->second].gasPrice())
+		auto cs = m_currentByAddressAndNonce.find(_transaction.from());
+		if (cs != m_currentByAddressAndNonce.end())
+		{
+			auto t = cs->second.find(_transaction.nonce());
+			if (t != cs->second.end())
+			{
+				if (_transaction.gasPrice() < (*t->second).transaction.gasPrice())
 					return ImportResult::OverbidGasPrice;
 				else
-				{
-					remove_WITH_LOCK(it->second);
-					break;
-				}
-			else if (m_future.count(it->second) && m_future[it->second].nonce() == _transaction.nonce())
-				if (_transaction.gasPrice() < m_future[it->second].gasPrice())
+					remove_WITH_LOCK((*t->second).transaction.sha3());
+			}
+		}
+		auto fs = m_future.find(_transaction.from());
+		if (fs != m_future.end())
+		{
+			auto t = fs->second.find(_transaction.nonce());
+			if (t != fs->second.end())
+			{
+				if (_transaction.gasPrice() < t->second.transaction.gasPrice())
 					return ImportResult::OverbidGasPrice;
 				else
 				{
-					remove_WITH_LOCK(it->second);
-					break;
+					fs->second.erase(t);
+					--m_futureSize;
 				}
-			else {}
-
+			}
+		}
 		// If valid, append to blocks.
 		insertCurrent_WITH_LOCK(make_pair(_h, _transaction));
 		m_known.insert(_h);
 		if (_cb)
 			m_callbacks[_h] = _cb;
 		clog(TransactionQueueTraceChannel) << "Queued vaguely legit-looking transaction" << _h;
+
+		while (m_current.size() > m_limit)
+		{
+			clog(TransactionQueueTraceChannel) << "Dropping out of bounds transaction" << _h;
+			remove_WITH_LOCK(m_current.rbegin()->transaction.sha3());
+		}
+
 		m_onReady();
 	}
 	catch (Exception const& _e)
@@ -163,93 +188,111 @@ u256 TransactionQueue::maxNonce(Address const& _a) const
 u256 TransactionQueue::maxNonce_WITH_LOCK(Address const& _a) const
 {
 	u256 ret = 0;
-	auto r = m_senders.equal_range(_a);
-	for (auto it = r.first; it != r.second; ++it)
-		if (m_current.count(it->second))
-		{
-//			cdebug << it->first << "1+" << m_current.at(it->second).nonce();
-			ret = max(ret, m_current.at(it->second).nonce() + 1);
-		}
-		else if (m_future.count(it->second))
-		{
-//			cdebug << it->first << "1+" << m_future.at(it->second).nonce();
-			ret = max(ret, m_future.at(it->second).nonce() + 1);
-		}
-		else
-		{
-			cwarn << "ERRROR!!!!! m_senders references non-current transaction";
-			cwarn << "Sender" << it->first << "has transaction" << it->second;
-			cwarn << "Count of m_current for" << it->second << "is" << m_current.count(it->second);
-		}
-	return ret;
+	auto cs = m_currentByAddressAndNonce.find(_a);
+	if (cs != m_currentByAddressAndNonce.end() && !cs->second.empty())
+		ret = cs->second.rbegin()->first;
+	auto fs = m_future.find(_a);
+	if (fs != m_future.end() && !fs->second.empty())
+		ret = std::max(ret, fs->second.rbegin()->first);
+	return ret + 1;
 }
 
 void TransactionQueue::insertCurrent_WITH_LOCK(std::pair<h256, Transaction> const& _p)
 {
-//	cdebug << "txQ::insertCurrent" << _p.first << _p.second.sender() << _p.second.nonce();
-	m_senders.insert(make_pair(_p.second.sender(), _p.first));
-	if (m_current.count(_p.first))
+	if (m_currentByHash.count(_p.first))
+	{
 		cwarn << "Transaction hash" << _p.first << "already in current?!";
-	m_current.insert(_p);
-}
+		return;
+	}
 
-bool TransactionQueue::remove_WITH_LOCK(h256 const& _txHash)
-{
-//	cdebug << "txQ::remove" << _txHash;
-	for (std::unordered_map<h256, Transaction>* pool: { &m_current, &m_future })
+	Transaction const& t = _p.second;
+	// Insert into current
+	auto inserted = m_currentByAddressAndNonce[t.from()].insert(std::make_pair(t.nonce(), PriorityQueue::iterator()));
+	PriorityQueue::iterator handle = m_current.emplace(VerifiedTransaction(t));
+	inserted.first->second = handle;
+	m_currentByHash[_p.first] = handle;
+
+	// Move following transactions from future to current
+	auto fs = m_future.find(t.from());
+	if (fs != m_future.end())
 	{
-		auto pit = pool->find(_txHash);
-		if (pit != pool->end())
+		u256 nonce = t.nonce() + 1;
+		auto fb = fs->second.find(nonce);
+		if (fb != fs->second.end())
 		{
-			auto r = m_senders.equal_range(pit->second.sender());
-			for (auto i = r.first; i != r.second; ++i)
-				if (i->second == _txHash)
-				{
-					m_senders.erase(i);
-					break;
-				}
-//			cdebug << "=> nonce" << pit->second.nonce();
-			pool->erase(pit);
-			return true;
+			auto ft = fb;
+			while (ft != fs->second.end() && ft->second.transaction.nonce() == nonce)
+			{
+				inserted = m_currentByAddressAndNonce[t.from()].insert(std::make_pair(ft->second.transaction.nonce(), PriorityQueue::iterator()));
+				PriorityQueue::iterator handle = m_current.emplace(move(ft->second));
+				inserted.first->second = handle;
+				m_currentByHash[(*handle).transaction.sha3()] = handle;
+				--m_futureSize;
+				++ft;
+				++nonce;
+			}
+			fs->second.erase(fb, ft);
+			if (fs->second.empty())
+				m_future.erase(t.from());
 		}
 	}
-	return false;
+}
+
+bool TransactionQueue::remove_WITH_LOCK(h256 const& _txHash)
+{
+	auto t = m_currentByHash.find(_txHash);
+	if (t == m_currentByHash.end())
+		return false;
+
+	Address from = (*t->second).transaction.from();
+	auto it = m_currentByAddressAndNonce.find(from);
+	assert (it != m_currentByAddressAndNonce.end());
+	it->second.erase((*t->second).transaction.nonce());
+	m_current.erase(t->second);
+	m_currentByHash.erase(t);
+	if (it->second.empty())
+		m_currentByAddressAndNonce.erase(it);
+	return true;
 }
 
 unsigned TransactionQueue::waiting(Address const& _a) const
 {
 	ReadGuard l(m_lock);
-	auto it = m_senders.equal_range(_a);
 	unsigned ret = 0;
-	for (auto i = it.first; i != it.second; ++i, ++ret) {}
+	auto cs = m_currentByAddressAndNonce.find(_a);
+	if (cs != m_currentByAddressAndNonce.end())
+		ret = cs->second.size();
+	auto fs = m_future.find(_a);
+	if (fs != m_future.end())
+		ret += fs->second.size();
 	return ret;
 }
 
-void TransactionQueue::setFuture(std::pair<h256, Transaction> const& _t)
+void TransactionQueue::setFuture(h256 const& _txHash)
 {
 //	cdebug << "txQ::setFuture" << _t.first;
 	WriteGuard l(m_lock);
-	if (m_current.count(_t.first))
-	{
-		m_future.insert(_t);
-		m_current.erase(_t.first);
-	}
-}
+	auto it = m_currentByHash.find(_txHash);
+	if (it == m_currentByHash.end())
+		return;
 
-void TransactionQueue::noteGood(std::pair<h256, Transaction> const& _t)
-{
-//	cdebug << "txQ::noteGood" << _t.first;
-	WriteGuard l(m_lock);
-	auto r = m_senders.equal_range(_t.second.sender());
-	for (auto it = r.first; it != r.second; ++it)
+	VerifiedTransaction const& st = *(it->second);
+
+	Address from = st.transaction.from();
+	auto& queue = m_currentByAddressAndNonce[from];
+	auto& target = m_future[from];
+	auto cutoff = queue.lower_bound(st.transaction.nonce());
+	for (auto m = cutoff; m != queue.end(); ++m)
 	{
-		auto fit = m_future.find(it->second);
-		if (fit != m_future.end())
-		{
-			m_current.insert(*fit);
-			m_future.erase(fit);
-		}
+		VerifiedTransaction& t = const_cast<VerifiedTransaction&>(*(m->second)); // set has only const iterators. Since we are moving out of container that's fine
+		m_currentByHash.erase(t.transaction.sha3());
+		target.emplace(t.transaction.nonce(), move(t));
+		m_current.erase(m->second);
+		++m_futureSize;
 	}
+	queue.erase(cutoff, queue.end());
+	if (queue.empty())
+		m_currentByAddressAndNonce.erase(from);
 }
 
 void TransactionQueue::drop(h256 const& _txHash)
@@ -265,3 +308,14 @@ void TransactionQueue::drop(h256 const& _txHash)
 
 	remove_WITH_LOCK(_txHash);
 }
+
+void TransactionQueue::clear()
+{
+	WriteGuard l(m_lock);
+	m_known.clear();
+	m_current.clear();
+	m_currentByAddressAndNonce.clear();
+	m_currentByHash.clear();
+	m_future.clear();
+	m_futureSize = 0;
+}
diff --git a/libethereum/TransactionQueue.h b/libethereum/TransactionQueue.h
index d9bfef847..d92a73dab 100644
--- a/libethereum/TransactionQueue.h
+++ b/libethereum/TransactionQueue.h
@@ -43,6 +43,7 @@ enum class IfDropped { Ignore, Retry };
 
 /**
  * @brief A queue of Transactions, each stored as RLP.
+ * Maintains a transaction queue sorted by nonce diff and gas price
  * @threadsafe
  */
 class TransactionQueue
@@ -50,6 +51,10 @@ class TransactionQueue
 public:
 	using ImportCallback = std::function<void(ImportResult)>;
 
+	/// @brief TransactionQueue
+	/// @param _limit Maximum number of pending transactions in the queue
+	/// @param _futureLimit Maximum number of future nonce transactions
+	TransactionQueue(unsigned _limit = 1024, unsigned _futureLimit = 1024): m_current(PriorityCompare { *this }), m_limit(_limit), m_futureLimit(_futureLimit) {}
 	ImportResult import(Transaction const& _tx, ImportCallback const& _cb = ImportCallback(), IfDropped _ik = IfDropped::Ignore);
 	ImportResult import(bytes const& _tx, ImportCallback const& _cb = ImportCallback(), IfDropped _ik = IfDropped::Ignore) { return import(&_tx, _cb, _ik); }
 	ImportResult import(bytesConstRef _tx, ImportCallback const& _cb = ImportCallback(), IfDropped _ik = IfDropped::Ignore);
@@ -57,17 +62,40 @@ public:
 	void drop(h256 const& _txHash);
 
 	unsigned waiting(Address const& _a) const;
-	std::unordered_map<h256, Transaction> transactions() const;
-	std::pair<unsigned, unsigned> items() const { ReadGuard l(m_lock); return std::make_pair(m_current.size(), m_future.size()); }
+	Transactions topTransactions(unsigned _limit) const;
+	h256Hash knownTransactions() const;
 	u256 maxNonce(Address const& _a) const;
+	void setFuture(h256 const& _t);
 
-	void setFuture(std::pair<h256, Transaction> const& _t);
-	void noteGood(std::pair<h256, Transaction> const& _t);
-
-	void clear() { WriteGuard l(m_lock); m_senders.clear(); m_known.clear(); m_current.clear(); m_future.clear(); }
+	void clear();
 	template <class T> Handler onReady(T const& _t) { return m_onReady.add(_t); }
 
 private:
+	struct VerifiedTransaction
+	{
+		VerifiedTransaction(Transaction const& _t): transaction(_t) {}
+		VerifiedTransaction(VerifiedTransaction&& _t): transaction(std::move(_t.transaction)) {}
+
+		VerifiedTransaction(VerifiedTransaction const&) = delete;
+		VerifiedTransaction operator=(VerifiedTransaction const&) = delete;
+
+		Transaction transaction;
+	};
+
+	struct PriorityCompare
+	{
+		TransactionQueue& queue;
+		bool operator()(VerifiedTransaction const& _first, VerifiedTransaction const& _second) const
+		{
+			u256 const& height1 = _first.transaction.nonce() - queue.m_currentByAddressAndNonce[_first.transaction.sender()].begin()->first;
+			u256 const& height2 = _second.transaction.nonce() - queue.m_currentByAddressAndNonce[_second.transaction.sender()].begin()->first;
+			return height1 < height2 || (height1 == height2 && _first.transaction.gasPrice() > _second.transaction.gasPrice());
+		}
+	};
+
+	// Use a set with dynamic comparator for minmax priority queue. The comparator takes into account min account nonce. Updating it does not affect the order.
+	using PriorityQueue = std::multiset<VerifiedTransaction, PriorityCompare>;
+
 	ImportResult check_WITH_LOCK(h256 const& _h, IfDropped _ik);
 	ImportResult manageImport_WITH_LOCK(h256 const& _h, Transaction const& _transaction, ImportCallback const& _cb);
 
@@ -77,12 +105,19 @@ private:
 
 	mutable SharedMutex m_lock;													///< General lock.
 	h256Hash m_known;															///< Hashes of transactions in both sets.
-	std::unordered_multimap<Address, h256> m_senders;							///< Mapping from the sender address to the transaction hash; useful for determining the nonce of a given sender.
-	std::unordered_map<h256, Transaction> m_current;							///< Map of SHA3(tx) to tx.
-	std::unordered_map<h256, Transaction> m_future;								///< For transactions that have a future nonce; we re-insert into current once the sender has a valid TX.
+
 	std::unordered_map<h256, std::function<void(ImportResult)>> m_callbacks;	///< Called once.
-	h256Hash m_dropped;															///< Transactions that have previously been dropped.
+	h256Hash m_dropped;															///< Transactions that have previously been dropped
+
+	PriorityQueue m_current;
+	std::unordered_map<h256, PriorityQueue::iterator> m_currentByHash;			///< Transaction hash to set ref
+	std::unordered_map<Address, std::map<u256, PriorityQueue::iterator>> m_currentByAddressAndNonce; ///< Transactions grouped by account and nonce
+	std::unordered_map<Address, std::map<u256, VerifiedTransaction>> m_future;	/// Future transactions
+
 	Signal m_onReady;															///< Called when a subsequent call to import transactions will return a non-empty container. Be nice and exit fast.
+	unsigned m_limit;															///< Max number of pending transactions
+	unsigned m_futureLimit;														///< Max number of future transactions
+	unsigned m_futureSize = 0;													///< Current number of future transactions
 };
 
 }
diff --git a/libethereum/VerifiedBlock.h b/libethereum/VerifiedBlock.h
index 6cafe4b2f..5d1efb7d0 100644
--- a/libethereum/VerifiedBlock.h
+++ b/libethereum/VerifiedBlock.h
@@ -43,7 +43,7 @@ struct VerifiedBlockRef
 /// @brief Verified block info, combines block data and verified info/transactions
 struct VerifiedBlock
 {
-	VerifiedBlock() {};
+	VerifiedBlock() {}
 
 	VerifiedBlock(BlockInfo&& _bi)
 	{
diff --git a/libp2p/Common.h b/libp2p/Common.h
index 445ba0cca..c124115f9 100644
--- a/libp2p/Common.h
+++ b/libp2p/Common.h
@@ -236,7 +236,7 @@ template <> struct hash<bi::address>
 			return boost::hash_range(range.begin(), range.end());
 		}
 		if (_a.is_unspecified())
-			return static_cast<size_t>(0x3487194039229152ul);  // Chosen by fair dice roll, guaranteed to be random
+			return static_cast<size_t>(0x3487194039229152ull);  // Chosen by fair dice roll, guaranteed to be random
 		return std::hash<std::string>()(_a.to_string());
 	}
 };
diff --git a/test/libethereum/blockchain.cpp b/test/libethereum/blockchain.cpp
index 0314de78b..6455eee17 100644
--- a/test/libethereum/blockchain.cpp
+++ b/test/libethereum/blockchain.cpp
@@ -200,8 +200,8 @@ void doBlockchainTests(json_spirit::mValue& _v, bool _fillin)
 
 				//get valid transactions
 				Transactions txList;
-				for (auto const& txi: txs.transactions())
-					txList.push_back(txi.second);
+				for (auto const& txi: txs.topTransactions(std::numeric_limits<unsigned>::max()))
+					txList.push_back(txi);
 				blObj["transactions"] = writeTransactionsToJson(txList);
 
 				BlockInfo current_BlockHeader = state.info();
diff --git a/test/libethereum/transactionqueue.cpp b/test/libethereum/transactionqueue.cpp
index ab85350a5..aa76681c5 100644
--- a/test/libethereum/transactionqueue.cpp
+++ b/test/libethereum/transactionqueue.cpp
@@ -61,4 +61,112 @@ BOOST_AUTO_TEST_CASE(maxNonce)
 
 }
 
+BOOST_AUTO_TEST_CASE(priority)
+{
+	dev::eth::TransactionQueue txq;
+
+	const u256 gasCostCheap =  10 * szabo;
+	const u256 gasCostMed =  20 * szabo;
+	const u256 gasCostHigh =  30 * szabo;
+	const u256 gas = 25000;
+	Address dest = Address("0x095e7baea6a6c7c4c2dfeb977efac326af552d87");
+	Secret sender1 = Secret("0x3333333333333333333333333333333333333333333333333333333333333333");
+	Secret sender2 = Secret("0x4444444444444444444444444444444444444444444444444444444444444444");
+	Transaction tx0(0, gasCostCheap, gas, dest, bytes(), 0, sender1 );
+	Transaction tx0_1(1, gasCostMed, gas, dest, bytes(), 0, sender1 );
+	Transaction tx1(0, gasCostCheap, gas, dest, bytes(), 1, sender1 );
+	Transaction tx2(0, gasCostHigh, gas, dest, bytes(), 0, sender2 );
+	Transaction tx3(0, gasCostCheap + 1, gas, dest, bytes(), 1, sender2 );
+	Transaction tx4(0, gasCostHigh, gas, dest, bytes(), 2, sender1 );
+	Transaction tx5(0, gasCostMed, gas, dest, bytes(), 2, sender2 );
+
+	txq.import(tx0);
+	BOOST_CHECK(Transactions { tx0 } == txq.topTransactions(256));
+	txq.import(tx0);
+	BOOST_CHECK(Transactions { tx0 } == txq.topTransactions(256));
+	txq.import(tx0_1);
+	BOOST_CHECK(Transactions { tx0_1 } == txq.topTransactions(256));
+	txq.import(tx1);
+	BOOST_CHECK((Transactions { tx0_1, tx1 }) == txq.topTransactions(256));
+	txq.import(tx2);
+	BOOST_CHECK((Transactions { tx2, tx0_1, tx1 }) == txq.topTransactions(256));
+	txq.import(tx3);
+	BOOST_CHECK((Transactions { tx2, tx0_1, tx1, tx3 }) == txq.topTransactions(256));
+	txq.import(tx4);
+	BOOST_CHECK((Transactions { tx2, tx0_1, tx1, tx3, tx4 }) == txq.topTransactions(256));
+	txq.import(tx5);
+	BOOST_CHECK((Transactions { tx2, tx0_1, tx1, tx3, tx5, tx4 }) == txq.topTransactions(256));
+
+	txq.drop(tx0_1.sha3());
+	BOOST_CHECK((Transactions { tx2, tx1, tx3, tx5, tx4 }) == txq.topTransactions(256));
+	txq.drop(tx1.sha3());
+	BOOST_CHECK((Transactions { tx2, tx3, tx5, tx4 }) == txq.topTransactions(256));
+	txq.drop(tx5.sha3());
+	BOOST_CHECK((Transactions { tx2, tx3, tx4 }) == txq.topTransactions(256));
+
+	Transaction tx6(0, gasCostMed, gas, dest, bytes(), 20, sender1 );
+	txq.import(tx6);
+	BOOST_CHECK((Transactions { tx2, tx3, tx4, tx6 }) == txq.topTransactions(256));
+
+	Transaction tx7(0, gasCostMed, gas, dest, bytes(), 2, sender2 );
+	txq.import(tx7);
+	BOOST_CHECK((Transactions { tx2, tx3, tx4, tx6, tx7 }) == txq.topTransactions(256));
+}
+
+BOOST_AUTO_TEST_CASE(future)
+{
+	dev::eth::TransactionQueue txq;
+
+	// from a94f5374fce5edbc8e2a8697c15331677e6ebf0b
+	const u256 gasCostMed =  20 * szabo;
+	const u256 gas = 25000;
+	Address dest = Address("0x095e7baea6a6c7c4c2dfeb977efac326af552d87");
+	Secret sender = Secret("0x3333333333333333333333333333333333333333333333333333333333333333");
+	Transaction tx0(0, gasCostMed, gas, dest, bytes(), 0, sender );
+	Transaction tx1(0, gasCostMed, gas, dest, bytes(), 1, sender );
+	Transaction tx2(0, gasCostMed, gas, dest, bytes(), 2, sender );
+	Transaction tx3(0, gasCostMed, gas, dest, bytes(), 3, sender );
+	Transaction tx4(0, gasCostMed, gas, dest, bytes(), 4, sender );
+
+	txq.import(tx0);
+	txq.import(tx1);
+	txq.import(tx2);
+	txq.import(tx3);
+	txq.import(tx4);
+	BOOST_CHECK((Transactions { tx0, tx1, tx2, tx3, tx4 }) == txq.topTransactions(256));
+
+	txq.setFuture(tx2.sha3());
+	BOOST_CHECK((Transactions { tx0, tx1 }) == txq.topTransactions(256));
+
+	Transaction tx2_2(1, gasCostMed, gas, dest, bytes(), 2, sender );
+	txq.import(tx2_2);
+	BOOST_CHECK((Transactions { tx0, tx1, tx2_2, tx3, tx4 }) == txq.topTransactions(256));
+}
+
+
+BOOST_AUTO_TEST_CASE(lmits)
+{
+	dev::eth::TransactionQueue txq(3, 3);
+	const u256 gasCostMed =  20 * szabo;
+	const u256 gas = 25000;
+	Address dest = Address("0x095e7baea6a6c7c4c2dfeb977efac326af552d87");
+	Secret sender = Secret("0x3333333333333333333333333333333333333333333333333333333333333333");
+	Secret sender2 = Secret("0x4444444444444444444444444444444444444444444444444444444444444444");
+	Transaction tx0(0, gasCostMed, gas, dest, bytes(), 0, sender );
+	Transaction tx1(0, gasCostMed, gas, dest, bytes(), 1, sender );
+	Transaction tx2(0, gasCostMed, gas, dest, bytes(), 2, sender );
+	Transaction tx3(0, gasCostMed, gas, dest, bytes(), 3, sender );
+	Transaction tx4(0, gasCostMed, gas, dest, bytes(), 4, sender );
+	Transaction tx5(0, gasCostMed + 1, gas, dest, bytes(), 0, sender2 );
+
+	txq.import(tx0);
+	txq.import(tx1);
+	txq.import(tx2);
+	txq.import(tx3);
+	txq.import(tx4);
+	txq.import(tx5);
+	BOOST_CHECK((Transactions { tx5, tx0, tx1 }) == txq.topTransactions(256));
+}
+
+
 BOOST_AUTO_TEST_SUITE_END()