diff --git a/targets/TARGET_STM/TARGET_STM32WB/device/stm32wbxx_ll_rtc.h b/targets/TARGET_STM/TARGET_STM32WB/device/stm32wbxx_ll_rtc.h
index 59f84e5764..c37c081c80 100644
--- a/targets/TARGET_STM/TARGET_STM32WB/device/stm32wbxx_ll_rtc.h
+++ b/targets/TARGET_STM/TARGET_STM32WB/device/stm32wbxx_ll_rtc.h
@@ -3091,7 +3091,7 @@ __STATIC_INLINE void LL_RTC_BAK_SetRegister(RTC_TypeDef *RTCx, uint32_t BackupRe
   */
 __STATIC_INLINE uint32_t LL_RTC_BAK_GetRegister(RTC_TypeDef *RTCx, uint32_t BackupRegister)
 {
-  const register __IO uint32_t *tmp;
+  register const __IO uint32_t *tmp;
 
   tmp = &(RTCx->BKP0R) + BackupRegister;