diff --git a/avr/send.c b/avr/send.c
index c6f0bf8..611cade 100644
--- a/avr/send.c
+++ b/avr/send.c
@@ -69,12 +69,12 @@ static void spi_start() {
     /*
      * Enable timer interrupt vector for match on OCR1A
      */
-    TIMSK0 = (1 << OCIE1A);
+    TIMSK1 = (1 << OCIE1A);
 }
 
 static void spi_end() {
     DDRB   &= ~((1 << DDB5) | (1 << DDB4) | (1 << DDB3));
-    TIMSK0 &= ~(1 << OCIE1A);
+    TIMSK1 &= ~(1 << OCIE1A);
     TCNT1   = 0;
     OCR1A   = TIMER1_INTERVAL;
     TCCR1B  = (1 << CS10);