diff --git a/docs/settings/moduleconfig/external-notification.mdx b/docs/settings/moduleconfig/external-notification.mdx
index de8a7dfc..259076cd 100644
--- a/docs/settings/moduleconfig/external-notification.mdx
+++ b/docs/settings/moduleconfig/external-notification.mdx
@@ -31,6 +31,10 @@ Specifies whether the external circuit is triggered when the device's GPIO is lo
 
 Specifies the GPIO that your external circuit is attached to on the device.
 
+:::info
+on ESP32 based boards, GPIOs 34 to 39 are GPIs – input only pins. These pins don’t have internal pull-up or pull-down resistors. They can’t be used as outputs, so you can NOT use these pins as outputs.
+:::
+
 ### How long monitored GPIO is triggered
 
 Specifies how long in milliseconds you would like your external circuit to be triggered.
@@ -156,4 +160,4 @@ Ideas for external hardware:
 ## Known Problems
 
 - This won't directly support a passive (normal) speaker as it does not generate any audio wave forms.
-- This module only monitors text messages. We won't trigger on any other packet types.
\ No newline at end of file
+- This module only monitors text messages. We won't trigger on any other packet types.