diff --git a/src/flash.c b/src/flash.c
index 1debb09..20de632 100644
--- a/src/flash.c
+++ b/src/flash.c
@@ -220,7 +220,7 @@ static inline
 uint8_t flash_erase_next_page()
 {
 	uint16_t mode = 0x81; // Page Erase
-	if (~b & 8)
+	if (~fs.block & 8)
 		fs.npages++;
 	uint8_t n = 0;
 	if (fs.page && !(fs.page & 0xff) && fs.npages & 0xff00) {
diff --git a/src/rtc.c b/src/rtc.c
index ee3486a..fe58a36 100644
--- a/src/rtc.c
+++ b/src/rtc.c
@@ -81,7 +81,7 @@ ISR(RTC_CNT_vect, ISR_NAKED)
 		"subi 	r24, -1"		"\n\t"
 		"sts 	clockh, r24"		"\n\t"
 		"lds 	r24, clockh+1"		"\n\t"
-		"sbci 	r24, -1"		"\n\t"
+		"sbci 	r24, 0"			"\n\t"
 		"sts 	clockh+1, r24"		"\n\t"
 		"2:"				"\n\t"
 		"pop 	r24"			"\n\t"
@@ -109,7 +109,7 @@ ISR(RTC_CNT_vect)
 	if (flag & RTC_CNT_bm)
 		RTC.CMP += rtc_config[1].val | rtc_config[2].val << 8;
 	if (flag & RTC_OVF_bm)
-		clock += 1;
+		clockh += 1;
 	return;
 }
 #endif