diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/device/StdDriver/m2351_clk.c b/targets/TARGET_NUVOTON/TARGET_M2351/device/StdDriver/m2351_clk.c
index d70b4da01d..3c20555727 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/device/StdDriver/m2351_clk.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/device/StdDriver/m2351_clk.c
@@ -114,7 +114,7 @@ void CLK_Idle(void)
   */
 //__NONSECURE_ENTRY_WEAK
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 uint32_t CLK_GetHXTFreq(void)
 {
     uint32_t u32Freq = 0UL;
@@ -142,7 +142,7 @@ uint32_t CLK_GetHXTFreq(void)
 
 //__NONSECURE_ENTRY_WEAK
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 uint32_t CLK_GetLXTFreq(void)
 {
     uint32_t u32Freq = 0UL;
@@ -169,7 +169,7 @@ uint32_t CLK_GetLXTFreq(void)
 
 //__NONSECURE_ENTRY_WEAK
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 uint32_t CLK_GetHCLKFreq(void)
 {
     SystemCoreClockUpdate();
@@ -186,7 +186,7 @@ uint32_t CLK_GetHCLKFreq(void)
 
 //__NONSECURE_ENTRY_WEAK
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 uint32_t CLK_GetPCLK0Freq(void)
 {
     SystemCoreClockUpdate();
@@ -203,7 +203,7 @@ uint32_t CLK_GetPCLK0Freq(void)
 
 //__NONSECURE_ENTRY_WEAK
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 uint32_t CLK_GetPCLK1Freq(void)
 {
     SystemCoreClockUpdate();
@@ -220,7 +220,7 @@ uint32_t CLK_GetPCLK1Freq(void)
 
 //__NONSECURE_ENTRY_WEAK
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 uint32_t CLK_GetCPUFreq(void)
 {
     uint32_t u32Freq, u32HclkSrc, u32HclkDiv;
@@ -1080,7 +1080,7 @@ void CLK_EnableSPDWKPin(uint32_t u32Port, uint32_t u32Pin, uint32_t u32TriggerTy
 
 //__NONSECURE_ENTRY_WEAK
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 uint32_t CLK_GetPLLClockFreq(void)
 {
     uint32_t u32PllFreq = 0UL, u32PllReg;
@@ -1169,7 +1169,7 @@ uint32_t CLK_GetPLLClockFreq(void)
 
 //__NONSECURE_ENTRY_WEAK
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 uint32_t CLK_GetModuleClockSource(uint32_t u32ModuleIdx)
 {
     uint32_t u32tmpVal = 0UL, u32tmpAddr = 0UL;
@@ -1229,7 +1229,7 @@ uint32_t CLK_GetModuleClockSource(uint32_t u32ModuleIdx)
 
 //__NONSECURE_ENTRY_WEAK
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 uint32_t CLK_GetModuleClockDivider(uint32_t u32ModuleIdx)
 {
     uint32_t u32tmpVal = 0UL, u32tmpAddr = 0UL;
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/device/StdDriver/m2351_sys.c b/targets/TARGET_NUVOTON/TARGET_M2351/device/StdDriver/m2351_sys.c
index b22542f6b9..6e0d25766f 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/device/StdDriver/m2351_sys.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/device/StdDriver/m2351_sys.c
@@ -165,7 +165,7 @@ void SYS_ResetCPU(void)
   * @details    This function reset selected module.
   */
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void SYS_ResetModule(uint32_t u32ModuleIndex)
 {
     uint32_t u32tmpVal = 0UL, u32tmpAddr = 0UL;
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/device/m2351_stddriver_sup.c b/targets/TARGET_NUVOTON/TARGET_M2351/device/m2351_stddriver_sup.c
index 62e26c1a36..258bc31dbf 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/device/m2351_stddriver_sup.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/device/m2351_stddriver_sup.c
@@ -133,7 +133,7 @@ static const nu_modidx_ns_t modidx_ns_tab[] = {
  */
 static bool check_mod_ns(int modclass, uint32_t modidx);
 
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void SYS_ResetModule_S(uint32_t u32ModuleIndex)
 {
     /* Guard access to secure module from non-secure domain */
@@ -145,7 +145,7 @@ void SYS_ResetModule_S(uint32_t u32ModuleIndex)
     SYS_ResetModule(u32ModuleIndex);
 }
 
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void CLK_SetModuleClock_S(uint32_t u32ModuleIndex, uint32_t u32ClkSrc, uint32_t u32ClkDiv)
 {
     /* Guard access to secure module from non-secure domain */
@@ -157,7 +157,7 @@ void CLK_SetModuleClock_S(uint32_t u32ModuleIndex, uint32_t u32ClkSrc, uint32_t
     CLK_SetModuleClock(u32ModuleIndex, u32ClkSrc, u32ClkDiv);
 }
 
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void CLK_EnableModuleClock_S(uint32_t u32ModuleIndex)
 {
     /* Guard access to secure module from non-secure domain */
@@ -169,7 +169,7 @@ void CLK_EnableModuleClock_S(uint32_t u32ModuleIndex)
     CLK_EnableModuleClock(u32ModuleIndex);
 }
 
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void CLK_DisableModuleClock_S(uint32_t u32ModuleIndex)
 {
     /* Guard access to secure module from non-secure domain */
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/pinmap.c b/targets/TARGET_NUVOTON/TARGET_M2351/pinmap.c
index e7d2dd9830..906c790a30 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/pinmap.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/pinmap.c
@@ -26,7 +26,7 @@
  */
 
 #if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void pin_function(PinName pin, int data)
 {
     MBED_ASSERT(pin != (PinName)NC);
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/rtc_api.c b/targets/TARGET_NUVOTON/TARGET_M2351/rtc_api.c
index fd54ce7c6e..e6b607e7bf 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/rtc_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/rtc_api.c
@@ -38,15 +38,15 @@
 /* As of ARM Compiler 6.9, we meet some NSC functions are missing in secure gateway
  * import library (cmse_lib.o) in secure build. Per test, we could get around it by
  * adding declaration for NSC functions. */
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void rtc_init(void);
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void rtc_free(void);
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 int rtc_isenabled(void);
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 time_t rtc_read(void);
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void rtc_write(time_t t);
 
 /* Micro seconds per second */
@@ -111,7 +111,7 @@ static void rtc_convert_datetime_hwrtc_to_tm(struct tm *datetime_tm, const S_RTC
 
 static const struct nu_modinit_s rtc_modinit = {RTC_0, RTC_MODULE, 0, 0, 0, RTC_IRQn, NULL};
 
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void rtc_init(void)
 {
     if (rtc_isenabled()) {
@@ -124,13 +124,13 @@ void rtc_init(void)
     rtc_write(0);
 }
 
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void rtc_free(void)
 {
     // N/A
 }
 
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 int rtc_isenabled(void)
 {
     // NOTE: To access (RTC) registers, clock must be enabled first.
@@ -145,7 +145,7 @@ int rtc_isenabled(void)
     return !! (rtc_base->INIT & RTC_INIT_ACTIVE_Msk);
 }
 
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 time_t rtc_read(void)
 {
     /* NOTE: After boot, RTC time registers are not synced immediately, about 1 sec latency.
@@ -186,7 +186,7 @@ time_t rtc_read(void)
     return t_present;
 }
 
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void rtc_write(time_t t)
 {
     if (! rtc_isenabled()) {
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/sleep.c b/targets/TARGET_NUVOTON/TARGET_M2351/sleep.c
index 49f32c3dbf..487da4799d 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/sleep.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/sleep.c
@@ -28,7 +28,7 @@
 /**
  * Enter idle mode, in which just CPU is halted.
  */
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void hal_sleep(void)
 {
     SYS_UnlockReg();
@@ -39,7 +39,7 @@ void hal_sleep(void)
 /**
  * Enter power-down mode, in which HXT/HIRC are halted.
  */
-__attribute__((cmse_nonsecure_entry))
+__NONSECURE_ENTRY
 void hal_deepsleep(void)
 {
     SYS_UnlockReg();