diff --git a/Compatible-boards.md b/Compatible-boards.md
index d60bd7d..e59b500 100644
--- a/Compatible-boards.md
+++ b/Compatible-boards.md
@@ -5,6 +5,8 @@ Arduino Board is "ESP32 Dev Module".
 
 Prototype development board schematics is available at https://github.com/sh123/lora_tracker.
 
+⚠ **ESP32 socket on the devboard is for narrow ESP32 boards, such as NodeMCU-32S!**
+
 ![Board](https://raw.githubusercontent.com/sh123/esp32_loraprs/master/extras/images/board.png)
 ![Device](https://raw.githubusercontent.com/sh123/esp32_loraprs/master/extras/images/device.png)