diff --git a/bsp/stm32/libraries/HAL_Drivers/drv_rtc.c b/bsp/stm32/libraries/HAL_Drivers/drv_rtc.c
index f62ed0b8f0..0161b0a93d 100644
--- a/bsp/stm32/libraries/HAL_Drivers/drv_rtc.c
+++ b/bsp/stm32/libraries/HAL_Drivers/drv_rtc.c
@@ -37,7 +37,7 @@ static time_t get_rtc_timestamp(void)
 {
     RTC_TimeTypeDef RTC_TimeStruct = {0};
     RTC_DateTypeDef RTC_DateStruct = {0};
-    struct tm tm_new;
+    struct tm tm_new = {0};
 
     HAL_RTC_GetTime(&RTC_Handler, &RTC_TimeStruct, RTC_FORMAT_BIN);
     HAL_RTC_GetDate(&RTC_Handler, &RTC_DateStruct, RTC_FORMAT_BIN);