diff --git a/pages/arduino_hid.md b/pages/arduino_hid.md
index 87a0e01..318d632 100644
--- a/pages/arduino_hid.md
+++ b/pages/arduino_hid.md
@@ -44,4 +44,4 @@ Next, you need to connect the Arduino pins to the female PS/2 port of your mothe
 Follow this diagram:
 | Female PS/2 port (front view) | Pinout |
 |-------------------------------|--------|
-| <img src="/img/ps2_kbd.png" alt="drawing" width="200"/> | Arduino pin 3 <-> PS/2 CLOCK<br>Arduino pin 2 <-> PS/2 DATA |
+| <img src="/img/ps2_kbd.png" alt="drawing" width="200"/> | Arduino pin 3 <-> PS/2 CLOCK<br>Arduino pin 2 <-> PS/2 DATA<br>Arduino GND pin <-> PS/2 GND |