diff --git a/README.md b/README.md
index 4d84061f..e7f4ed56 100644
--- a/README.md
+++ b/README.md
@@ -285,6 +285,8 @@ More information about the controller can be found at the following sites:
 
 The shield is using SPI for communicating with the MAX3421E USB host controller. It uses the SCK, MISO and MOSI pins via the ICSP on your board.
 
+Note this means that it uses pin 13, 12, 11 on an Arduino Uno, so these pins can not be used for anything else!
+
 Furthermore it uses one pin as SS and one INT pin. These are by default located on pin 10 and 9 respectively. They can easily be reconfigured in case you need to use them for something else by cutting the jumper on the shield and then solder a wire from the pad to the new pin.
 
 After that you need modify the following entry in [UsbCore.h](UsbCore.h):