diff --git a/mix/MixClient.cpp b/mix/MixClient.cpp
index 94bd0d71f..09fed6fc6 100644
--- a/mix/MixClient.cpp
+++ b/mix/MixClient.cpp
@@ -98,22 +98,30 @@ void MixClient::resetState(std::unordered_map<Address, Account> const& _accounts
 	m_executions.clear();
 }
 
-Transaction MixClient::replaceGas(Transaction const& _t, u256 const& _gas)
+Transaction MixClient::replaceGas(Transaction const& _t, Secret const& _secret, u256 const& _gas)
 {
 	Transaction ret;
-	if (_t.isCreation())
-		ret = Transaction(_t.value(), _t.gasPrice(), _gas, _t.data(), _t.nonce());
+	if (_secret)
+	{
+		if (_t.isCreation())
+			ret = Transaction(_t.value(), _t.gasPrice(), _gas, _t.data(), _t.nonce(), _secret);
+		else
+			ret = Transaction(_t.value(), _t.gasPrice(), _gas, _t.receiveAddress(), _t.data(), _t.nonce(), _secret);
+	}
 	else
-		ret = Transaction(_t.value(), _t.gasPrice(), _gas, _t.receiveAddress(), _t.data(), _t.nonce());
-	ret.forceSender(_t.safeSender());
+	{
+		if (_t.isCreation())
+			ret = Transaction(_t.value(), _t.gasPrice(), _gas, _t.data(), _t.nonce());
+		else
+			ret = Transaction(_t.value(), _t.gasPrice(), _gas, _t.receiveAddress(), _t.data(), _t.nonce());
+		ret.forceSender(_t.safeSender());
+	}
 	return ret;
 }
 
-void MixClient::executeTransaction(Transaction const& _t, State& _state, bool _call, bool _gasAuto)
+void MixClient::executeTransaction(Transaction const& _t, Secret const& _secret, State& _state, bool _call, bool _gasAuto)
 {
-	Transaction t = _gasAuto ? replaceGas(_t, m_state.gasLimitRemaining()) : _t;
-	bytes rlp = t.rlp();
-
+	Transaction t = _gasAuto ? replaceGas(_t, Secret(), m_state.gasLimitRemaining()) : _t;
 	// do debugging run first
 	LastHashes lastHashes(256);
 	lastHashes[0] = bc().numberHash(bc().number());
@@ -123,7 +131,7 @@ void MixClient::executeTransaction(Transaction const& _t, State& _state, bool _c
 	State execState = _state;
 	execState.addBalance(t.sender(), t.gas() * t.gasPrice()); //give it enough balance for gas estimation
 	Executive execution(execState, lastHashes, 0);
-	execution.initialize(&rlp);
+	execution.initialize(t);
 	execution.execute();
 	std::vector<MachineState> machineStates;
 	std::vector<unsigned> levels;
@@ -222,7 +230,7 @@ void MixClient::executeTransaction(Transaction const& _t, State& _state, bool _c
 	// execute on a state
 	if (!_call)
 	{
-		t = _gasAuto ? replaceGas(_t, d.gasUsed) : _t;
+		t = _gasAuto ? replaceGas(_t, _secret, d.gasUsed) : _t;
 		er =_state.execute(lastHashes, t);
 		if (t.isCreation() && _state.code(d.contractAddress).empty())
 			BOOST_THROW_EXCEPTION(OutOfGas() << errinfo_comment("Not enough gas for contract deployment"));
@@ -285,7 +293,7 @@ void MixClient::submitTransaction(Secret _secret, u256 _value, Address _dest, by
 	WriteGuard l(x_state);
 	u256 n = m_state.transactionsFrom(toAddress(_secret));
 	Transaction t(_value, _gasPrice, _gas, _dest, _data, n, _secret);
-	executeTransaction(t, m_state, false, _gasAuto);
+	executeTransaction(t, _secret, m_state, false, _gasAuto);
 }
 
 Address MixClient::submitTransaction(Secret _secret, u256 _endowment, bytes const& _init, u256 _gas, u256 _gasPrice, bool _gasAuto)
@@ -293,7 +301,7 @@ Address MixClient::submitTransaction(Secret _secret, u256 _endowment, bytes cons
 	WriteGuard l(x_state);
 	u256 n = m_state.transactionsFrom(toAddress(_secret));
 	eth::Transaction t(_endowment, _gasPrice, _gas, _init, n, _secret);
-	executeTransaction(t, m_state, false, _gasAuto);
+	executeTransaction(t, _secret, m_state, false, _gasAuto);
 	Address address = right160(sha3(rlpList(t.sender(), t.nonce())));
 	return address;
 }
@@ -307,9 +315,8 @@ dev::eth::ExecutionResult MixClient::call(Address const& _from, u256 _value, Add
 	t.forceSender(_from);
 	if (_ff == FudgeFactor::Lenient)
 		temp.addBalance(_from, (u256)(t.gasRequired() * t.gasPrice() + t.value()));
-	bytes rlp = t.rlp();
 	WriteGuard lw(x_state); //TODO: lock is required only for last execution state
-	executeTransaction(t, temp, true, _gasAuto);
+	executeTransaction(t, Secret(), temp, true, _gasAuto);
 	return lastExecution().result;
 }
 
@@ -343,7 +350,7 @@ dev::eth::ExecutionResult MixClient::create(Address const& _from, u256 _value, b
 	if (_ff == FudgeFactor::Lenient)
 		temp.addBalance(_from, (u256)(t.gasRequired() * t.gasPrice() + t.value()));
 	WriteGuard lw(x_state); //TODO: lock is required only for last execution state
-	executeTransaction(t, temp, true, false);
+	executeTransaction(t, Secret(), temp, true, false);
 	return lastExecution().result;
 }
 
diff --git a/mix/MixClient.h b/mix/MixClient.h
index f7687c488..5988286d0 100644
--- a/mix/MixClient.h
+++ b/mix/MixClient.h
@@ -87,9 +87,9 @@ protected:
 	virtual void prepareForTransaction() override {}
 
 private:
-	void executeTransaction(dev::eth::Transaction const& _t, eth::State& _state, bool _call, bool _gasAuto);
+	void executeTransaction(dev::eth::Transaction const& _t, dev::Secret const& _secret, eth::State& _state, bool _call, bool _gasAuto);
 	void noteChanged(h256Set const& _filters);
-	dev::eth::Transaction replaceGas(dev::eth::Transaction const& _t, dev::u256 const& _gas);
+	dev::eth::Transaction replaceGas(dev::eth::Transaction const& _t, dev::Secret const& _secret, dev::u256 const& _gas);
 
 	eth::State m_state;
 	eth::State m_startState;