diff --git a/src/timer.inc b/src/timer.inc
index 43b80ad..5d5ad08 100644
--- a/src/timer.inc
+++ b/src/timer.inc
@@ -31,7 +31,7 @@ timer0_isr:
 
     reti
 
-.timer0_stop
+.timer0_stop:
     sts     timer0_overflow_count,  r0                  ; Reset overflow byte
     out     TCCR0B,     r0                              ; Stop timer0 by clearing prescaler