diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c
index 9812120..ba795a4 100644
--- a/drivers/rtc/rtc-lib.c
+++ b/drivers/rtc/rtc-lib.c
@@ -94,12 +94,12 @@
 int rtc_valid_tm(struct rtc_time *tm)
 {
 	if (tm->tm_year < 70
-		|| tm->tm_mon >= 12
+		|| ((unsigned)tm->tm_mon) >= 12
 		|| tm->tm_mday < 1
 		|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
-		|| tm->tm_hour >= 24
-		|| tm->tm_min >= 60
-		|| tm->tm_sec >= 60)
+		|| ((unsigned)tm->tm_hour) >= 24
+		|| ((unsigned)tm->tm_min) >= 60
+		|| ((unsigned)tm->tm_sec) >= 60)
 		return -EINVAL;
 
 	return 0;
diff --git a/drivers/rtc/rtc-proc.c b/drivers/rtc/rtc-proc.c
index 1b2c2ca..2943d83 100644
--- a/drivers/rtc/rtc-proc.c
+++ b/drivers/rtc/rtc-proc.c
@@ -61,7 +61,7 @@
 			seq_printf(seq, "%02d-", alrm.time.tm_mon + 1);
 		else
 			seq_printf(seq, "**-");
-		if ((unsigned int)alrm.time.tm_mday <= 31)
+		if (alrm.time.tm_mday && (unsigned int)alrm.time.tm_mday <= 31)
 			seq_printf(seq, "%02d\n", alrm.time.tm_mday);
 		else
 			seq_printf(seq, "**\n");