diff --git a/Sideboards.md b/Sideboards.md
index 0bb66df..0d162d6 100644
--- a/Sideboards.md
+++ b/Sideboards.md
@@ -13,6 +13,7 @@ The [STM](https://github.com/EFeru/hoverboard-sideboard-hack-STM) firmware can b
 * STM32F103C8T6
 * GD32F103C8T6
 
+⚠️ Don't mix mainboards and sideboards that don't belong together unless you checked the polarity on the connectors is not reversed ⚠️
 
 Those boards can have different IMUs, not all are fully supported:
 |IMU|Datasheet|Raw<br>Accel.<br>Data|Raw<br>Gyro<br>Data|DMP<br>Available|DMP<br>Supported|Comment|