diff --git a/api/arduino/sonoff.ino.bin b/api/arduino/sonoff.ino.bin
index 693ee4225..061eb83c7 100644
Binary files a/api/arduino/sonoff.ino.bin and b/api/arduino/sonoff.ino.bin differ
diff --git a/sonoff/sonoff_template.h b/sonoff/sonoff_template.h
index 88617dba3..b664637c5 100644
--- a/sonoff/sonoff_template.h
+++ b/sonoff/sonoff_template.h
@@ -149,7 +149,7 @@ const mytmplt modules[MAXMODULE] PROGMEM = {
      GPIO_KEY1,        // GPIO00 Button 1
      0,
      GPIO_USER,        // GPIO02 Optional sensor
-     0,
+     GPIO_USER,        // GPIO03 Serial TXD and Optional sensor
      GPIO_REL3,        // GPIO04 Sonoff 4CH Red Led and Relay 3 (0 = Off, 1 = On)
      GPIO_REL2,        // GPIO05 Sonoff 4CH Red Led and Relay 2 (0 = Off, 1 = On)
      0, 0, 0,