1 files changed, 1 insertions, 1 deletions

diff --git a/dong.c b/dong.c
index 70006dc..1ef872f 100644
--- a/dong.c
+++ b/dong.c
@@ -14,7 +14,7 @@
 #define RX_PCMSK       PCMSK2
 #define RX_PCINTVEC    PCINT2_vect
 
-static int rxdr = 0;
+static volatile int rxdr = 0;
 
 int main(void)
 {