diff --git a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/gpio_api.c b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/gpio_api.c
index ffdad22b9f..4efcc46283 100644
--- a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/gpio_api.c
+++ b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/gpio_api.c
@@ -37,7 +37,7 @@ void gpio_init(gpio_t *obj, PinName pin, PinDirection direction) {
     obj->pin = pin;
     LPC_GPIO_TypeDef *port_reg = ((LPC_GPIO_TypeDef *) (LPC_GPIO0_BASE + (((pin & 0xF000) >> PORT_SHIFT) * 0x10000)));
 
-    obj->reg_mask_read = &port_reg->MASKED_ACCESS[gpio_set(pin) + 1];
+    obj->reg_mask_read = &port_reg->MASKED_ACCESS[1 << gpio_set(pin)];
     obj->reg_dir       = &port_reg->DIR;
     obj->reg_write     = &port_reg->DATA;
     
diff --git a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/i2c_api.c b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/i2c_api.c
index 6fb7b23850..9a58c8e93a 100644
--- a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/i2c_api.c
+++ b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/i2c_api.c
@@ -383,5 +383,7 @@ void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask) {
     if ((idx >= 0) && (idx <= 3)) {
         addr = ((uint32_t)obj->i2c) + I2C_addr_offset[0][idx];
         *((uint32_t *) addr) = address & 0xFF;
+        addr = ((uint32_t)obj->i2c) + I2C_addr_offset[1][idx];
+        *((uint32_t *) addr) = mask & 0xFE;
     }
 }
diff --git a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/serial_api.c b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/serial_api.c
index 6b12c50345..18b1bd9a7e 100644
--- a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/serial_api.c
+++ b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX/serial_api.c
@@ -249,12 +249,6 @@ int serial_getc(serial_t *obj) {
 void serial_putc(serial_t *obj, int c) {
     while (!serial_writable(obj));
     obj->uart->THR = c;
-    
-#warning TODO(@toyowata): need to fix a full-duplex bug? https://mbed.org/forum/bugs-suggestions/topic/4473/
-    uint32_t lsr = obj->uart->LSR;
-    lsr = lsr;
-    uint32_t thr = obj->uart->THR;
-    thr = thr;
 }
 
 int serial_readable(serial_t *obj) {