diff --git a/devices/sonoff.rst b/devices/sonoff.rst
index 5c082f784..9ba16cbd6 100644
--- a/devices/sonoff.rst
+++ b/devices/sonoff.rst
@@ -210,6 +210,7 @@ Sonoff T1 1CH, 2CH, 3CH
     GPIO5, Relay 2 and Blue LED,
     GPIO10, Button 3 (inverted),
     GPIO4, Relay 3 and Blue LED,
+    GPIO13, Blue LED (inverted),
     GPIO1, UART TX pin (for external sensors)
     GPIO3, UART RX pin (for external sensors)