diff --git a/timex-datalink-arduino.ino b/timex-datalink-arduino.ino
index 5692db9..8918984 100644
--- a/timex-datalink-arduino.ino
+++ b/timex-datalink-arduino.ino
@@ -5,7 +5,7 @@
 
 #define HANDSHAKE_STOP 'U'
 #define HANDSHAKE_START '?'
-#define HANDSHAKE_PAYLOAD "126\r M764 rev 764002"
+#define HANDSHAKE_PAYLOAD "M764"
 
 #define PING_EXPIRE_MS 1000