diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c
index a9db79f80951c4b45e2456cb4e911ef95aebd86e..48227002bbfd9a09e29b0b22dec04e18f97e95ee 100644
--- a/drivers/rtc/rtc-lib.c
+++ b/drivers/rtc/rtc-lib.c
@@ -101,7 +101,7 @@ int rtc_valid_tm(struct rtc_time *tm)
 		|| ((unsigned)tm->tm_mon) >= 12
 		|| tm->tm_mday < 1
 		|| tm->tm_year > (INT_MAX - 1900)
-		|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
+		|| tm->tm_mday > rtc_month_days(tm->tm_mon, ((unsigned)tm->tm_year + 1900))
 		|| ((unsigned)tm->tm_hour) >= 24
 		|| ((unsigned)tm->tm_min) >= 60
 		|| ((unsigned)tm->tm_sec) >= 60)
@@ -117,8 +117,8 @@ EXPORT_SYMBOL(rtc_valid_tm);
  */
 time64_t rtc_tm_to_time64(struct rtc_time *tm)
 {
-	return mktime64(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
-			tm->tm_hour, tm->tm_min, tm->tm_sec);
+	return mktime64(((unsigned)tm->tm_year + 1900), tm->tm_mon + 1,
+			tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
 }
 EXPORT_SYMBOL(rtc_tm_to_time64);