diff --git a/cores/arduino/Wire.cpp b/cores/arduino/Wire.cpp
index 0a51eb8..2499bbf 100644
--- a/cores/arduino/Wire.cpp
+++ b/cores/arduino/Wire.cpp
@@ -117,7 +117,7 @@ uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity) {
 
   // perform blocking read into buffer
   I2C_M_SETUP_Type transferMCfg;
-  transferMCfg.sl_addr7bit = address >> 1; // not sure about the right shift
+  transferMCfg.sl_addr7bit = address;
   transferMCfg.tx_data = NULL;
   transferMCfg.tx_length = 0;
   transferMCfg.rx_data = rxBuffer;
@@ -153,7 +153,7 @@ void TwoWire::beginTransmission(int address) {
 uint8_t TwoWire::endTransmission(void) {
   // transmit buffer (blocking)
   I2C_M_SETUP_Type transferMCfg;
-  transferMCfg.sl_addr7bit = txAddress >> 1; // not sure about the right shift
+  transferMCfg.sl_addr7bit = txAddress;
   transferMCfg.tx_data = txBuffer;
   transferMCfg.tx_length = txBufferLength;
   transferMCfg.rx_data = NULL;
diff --git a/system/CMSIS/driver/lpc17xx_i2c.c b/system/CMSIS/driver/lpc17xx_i2c.c
index 99b29e0..2aa648f 100644
--- a/system/CMSIS/driver/lpc17xx_i2c.c
+++ b/system/CMSIS/driver/lpc17xx_i2c.c
@@ -516,9 +516,9 @@ int32_t I2C_MasterHanleStates(LPC_I2C_TypeDef  *I2Cx, uint32_t CodeStatus, I2C_M
 			Ret = I2C_BYTE_RECV;
 			break;
 		case I2C_I2STAT_M_RX_DAT_ACK:
-			if (TransferCfg->rx_count <TransferCfg->rx_length)
+			if (TransferCfg->rx_count < TransferCfg->rx_length)
 			{
-				if (TransferCfg->rx_count < (TransferCfg->rx_length - 2))
+				if (TransferCfg->rx_count < (TransferCfg->rx_length - 1))
 				{
 					I2C_GetByte(I2Cx, &tmp, TRUE);