diff --git a/libethash-cuda/ethash_cuda_miner_kernel.cu b/libethash-cuda/ethash_cuda_miner_kernel.cu
index 58f46edc8..8064662b4 100644
--- a/libethash-cuda/ethash_cuda_miner_kernel.cu
+++ b/libethash-cuda/ethash_cuda_miner_kernel.cu
@@ -11,7 +11,7 @@
 #include "dagger_shuffled.cuh"
 
 __global__ void 
-__launch_bounds__(128, 7)
+__launch_bounds__(896, 1)
 ethash_search(
 	volatile uint32_t* g_output,
 	uint64_t start_nonce
diff --git a/libethcore/EthashCUDAMiner.cpp b/libethcore/EthashCUDAMiner.cpp
index 3438d1d10..38a775c1b 100644
--- a/libethcore/EthashCUDAMiner.cpp
+++ b/libethcore/EthashCUDAMiner.cpp
@@ -219,13 +219,14 @@ bool EthashCUDAMiner::configureGPU(
 	uint64_t _currentBlock
 	)
 {
-	
+	_blockSize = ((_blockSize + 7) / 8) * 8;
+	/*
 	if (_blockSize != 32 && _blockSize != 64 && _blockSize != 128)
 	{
 		cout << "Given localWorkSize of " << toString(_blockSize) << "is invalid. Must be either 32,64 or 128" << endl;
 		return false;
 	}
-	
+	*/
 	if (!ethash_cuda_miner::configureGPU(
 		s_devices,
 		_blockSize,
diff --git a/libethcore/EthashGPUMiner.cpp b/libethcore/EthashGPUMiner.cpp
index bad845cbc..dc09462f9 100644
--- a/libethcore/EthashGPUMiner.cpp
+++ b/libethcore/EthashGPUMiner.cpp
@@ -213,12 +213,14 @@ bool EthashGPUMiner::configureGPU(
 	s_platformId = _platformId;
 	s_deviceId = _deviceId;
 
+	_localWorkSize = ((_localWorkSize + 7) / 8) * 8;
+	/*
 	if (_localWorkSize != 32 && _localWorkSize != 64 && _localWorkSize != 128 && _localWorkSize != 256)
 	{
 		cout << "Given localWorkSize of " << toString(_localWorkSize) << "is invalid. Must be either 32,64,128 or 256" << endl;
 		return false;
 	}
-
+	*/
 	if (!ethash_cl_miner::configureGPU(
 			_platformId,
 			_localWorkSize,
diff --git a/libstratum/EthStratumClient.cpp b/libstratum/EthStratumClient.cpp
index a960cdb9b..862dc373f 100644
--- a/libstratum/EthStratumClient.cpp
+++ b/libstratum/EthStratumClient.cpp
@@ -16,8 +16,6 @@ EthStratumClient::EthStratumClient(GenericFarm<EthashProofOfWork> * f, MinerType
 	m_connected = false;
 	m_precompute = true;
 	m_pending = 0;
-	
-
 	p_farm = f;
 	connect();
 }
@@ -119,13 +117,16 @@ void EthStratumClient::connect_handler(const boost::system::error_code& ec, tcp:
 }
 
 void EthStratumClient::readline() {
-
+	m_mtx.lock();
 	if (m_pending == 0) {
 		async_read_until(m_socket, m_responseBuffer, "\n",
 			boost::bind(&EthStratumClient::readResponse, this,
 			boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred));
+	
 		m_pending++;
+		
 	}
+	m_mtx.unlock();
 }
 
 void EthStratumClient::handleResponse(const boost::system::error_code& ec) {
@@ -141,7 +142,9 @@ void EthStratumClient::handleResponse(const boost::system::error_code& ec) {
 
 void EthStratumClient::readResponse(const boost::system::error_code& ec, std::size_t bytes_transferred)
 {
+	m_mtx.lock();
 	m_pending = m_pending > 0 ? m_pending - 1 : 0;
+	m_mtx.unlock();
 
 	if (!ec)
 	{
diff --git a/libstratum/EthStratumClient.h b/libstratum/EthStratumClient.h
index 661c0fc34..447356f79 100644
--- a/libstratum/EthStratumClient.h
+++ b/libstratum/EthStratumClient.h
@@ -48,6 +48,7 @@ private:
 	bool   m_connected;
 	bool   m_precompute;
 
+	boost::mutex m_mtx;
 	int m_pending;
 	string m_response;