diff --git a/Expanding-Sonoffs.md b/Expanding-Sonoffs.md
index 4d760e3b..45a66388 100644
--- a/Expanding-Sonoffs.md
+++ b/Expanding-Sonoffs.md
@@ -41,7 +41,7 @@ To make a link between the different naming schemes of pins, connectors and logi
 
 ## Restrictions
 
-Don't use GPIO: 0, 1, 2, 6-11, 15, 16 if you can avoid it. 3 is RX, so best to avoid also. That leaves 4, 5, 12, 13, 14 that don't have constraints. The others can be used, but you have to mind the [constraints](https://github.com/arendst/Sonoff-Tasmota/wiki/Expanding-Sonoffs#the-esp8266---hardware-more-info).
+Don't use GPIO: 0, 1, 2, 6-11, 15, 16 if you can avoid it. 3 is RX, so best to avoid also (PWM not working here). That leaves 4, 5, 12, 13, 14 that don't have constraints. The others can be used, but you have to mind the [constraints](https://github.com/arendst/Sonoff-Tasmota/wiki/Expanding-Sonoffs#the-esp8266---hardware-more-info).
 
 # Examples
 ## Connect switch