diff --git a/Expanding-4CH.md b/Expanding-4CH.md
index 9832fa75..95dd17b2 100644
--- a/Expanding-4CH.md
+++ b/Expanding-4CH.md
@@ -37,6 +37,7 @@ Sonoff-Tasmota is also configured with DS18x20 on GPIO2 and it works !
 |![](https://github.com/gtortone/Sonoff-Tasmota/blob/development/_temp_imgs/Sonoff-Configure-Module.png)|![](https://github.com/gtortone/Sonoff-Tasmota/blob/development/_temp_imgs/Sonoff-Main-Menu.png)|
 |---|---|
 
-
+****Note****: source file [sonoff/sonoff_template.h ](https://github.com/arendst/Sonoff-Tasmota/blob/development/sonoff/sonoff_template.h) provides the configuration on Sonoff 4CH and it is also possible to use GPIO16 (as in the screenshot above) but be aware that no interrupts can be used on GPIO16 and
+you could have problems with some sensors.