diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
index 90cf0a6ff23e3cce363958cb0c3e81cde08c14af..dd14e202c2c8cbaafe4ed261cab01835a16f8f89 100644
--- a/drivers/rtc/rtc-rs5c372.c
+++ b/drivers/rtc/rtc-rs5c372.c
@@ -207,7 +207,7 @@ static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	struct rs5c372	*rs5c = i2c_get_clientdata(client);
-	unsigned char	buf[8];
+	unsigned char	buf[7];
 	int		addr;
 
 	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "