diff --git a/rtc.c b/rtc.c
index 589e1d4..5076b81 100644
--- a/rtc.c
+++ b/rtc.c
@@ -25,6 +25,7 @@ ISR(TIMER2_OVF_vect) {
 void rtc_init(uint32_t rtc_time)
 {
   // Stop all interrupts
+  uint8_t sreg = SREG;
   cli();
   TCCR2B = 0;
   TCCR2A = 0;
@@ -37,6 +38,7 @@ void rtc_init(uint32_t rtc_time)
   TCCR2B = (1<<CS22)|(1<<CS20);
   
   TIMSK2 = (1<<TOIE2); // enable overflow interrupt
+  SREG = sreg;
 }
 
 
diff --git a/timer.c b/timer.c
index 1ba5e7b..9607683 100644
--- a/timer.c
+++ b/timer.c
@@ -32,6 +32,7 @@ ISR(TIMER0_COMPA_vect) {
 
 void timer_init(void)
 {
+  uint8_t sreg = SREG;
   // Stop all interrupts
   cli();
 
@@ -55,7 +56,7 @@ void timer_init(void)
 
   // Interrupts setzen
   TIMSK0 |= (1<<OCIE0A);
-
+  SREG = sreg;
 }