1 files changed, 1 insertions, 1 deletions
diff --git a/timer.h b/timer.h
index 8ddf9e7e28..2dfa08a0f8 100644
--- a/timer.h
+++ b/timer.h
@@ -6,7 +6,7 @@
 #define TIMER_DIFF(a, b) ((a) >= (b) ?  (a) - (b) : UINT16_MAX - (b) + (a))
 
 
-extern uint16_t timer_count;
+extern volatile uint16_t timer_count;
 
 
 void timer_init(void);