diff --git a/libraries/mbed/common/pinmap_common.c b/libraries/mbed/common/pinmap_common.c
index 3abc2855d0..66ccf963ce 100644
--- a/libraries/mbed/common/pinmap_common.c
+++ b/libraries/mbed/common/pinmap_common.c
@@ -45,7 +45,7 @@ uint32_t pinmap_merge(uint32_t a, uint32_t b) {
 }
 
 uint32_t pinmap_peripheral(PinName pin, const PinMap* map) {
-    if (pin == (uint32_t)NC)
+    if (pin == (PinName)NC)
         return (uint32_t)NC;
 
     while (map->pin != NC) {
diff --git a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/analogin_api.c b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/analogin_api.c
index 31f6c48cbf..982845b2c2 100644
--- a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/analogin_api.c
+++ b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/analogin_api.c
@@ -44,7 +44,7 @@ static const PinMap PinMap_ADC[] = {
 
 void analogin_init(analogin_t *obj, PinName pin) {
     obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
-    if (obj->adc == (uint32_t)NC) {
+    if (obj->adc == (ADCName)NC) {
         error("ADC pin mapping failed");
     }
     
diff --git a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/analogout_api.c b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/analogout_api.c
index d2704f37e4..103b644f17 100644
--- a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/analogout_api.c
+++ b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/analogout_api.c
@@ -26,7 +26,7 @@ static const PinMap PinMap_DAC[] = {
 
 void analogout_init(dac_t *obj, PinName pin) {
     obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
-    if (obj->dac == (uint32_t)NC) {
+    if (obj->dac == (DACName)NC) {
         error("DAC pin mapping failed");
     }
     
diff --git a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/pinmap.c b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/pinmap.c
index 64d01d3e1e..be017ce181 100644
--- a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/pinmap.c
+++ b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/pinmap.c
@@ -17,7 +17,7 @@
 #include "error.h"
 
 void pin_function(PinName pin, int function) {
-    if (pin == (uint32_t)NC) return;
+    if (pin == (PinName)NC) return;
     
     uint32_t pin_number = (uint32_t)pin - (uint32_t)P0_0;
     int index = pin_number >> 4;
@@ -28,7 +28,7 @@ void pin_function(PinName pin, int function) {
 }
 
 void pin_mode(PinName pin, PinMode mode) {
-    if (pin == (uint32_t)NC) { return; }
+    if (pin == (PinName)NC) { return; }
     
     uint32_t pin_number = (uint32_t)pin - (uint32_t)P0_0;
     int index = pin_number >> 5;
diff --git a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/pwmout_api.c b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/pwmout_api.c
index 93cf235201..b4e8bc6acf 100644
--- a/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/pwmout_api.c
+++ b/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC176X/pwmout_api.c
@@ -57,7 +57,7 @@ static unsigned int pwm_clock_mhz;
 void pwmout_init(pwmout_t* obj, PinName pin) {
     // determine the channel
     PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
-    if (pwm == (uint32_t)NC)
+    if (pwm == (PWMName)NC)
         error("PwmOut pin mapping failed");
     
     obj->pwm = pwm;