diff --git a/Device-Tests-&-Coverage-Report.md b/Device-Tests-&-Coverage-Report.md
index 2ddef43..0416cbe 100644
--- a/Device-Tests-&-Coverage-Report.md
+++ b/Device-Tests-&-Coverage-Report.md
@@ -15,6 +15,8 @@ You need python + [pyserial 3.4](https://pythonhosted.org/pyserial/) which inclu
 
 On Linux the ``rfc2217_server.py`` is typically available in ``usr/share/doc/python-serial/examples``. On Windows you have to take it from github.
 
+On a Raspi 3 you have to [configure](https://www.raspberrypi.org/documentation/configuration/uart.md) the PL011-UART instead of the mini-UART for the GPIO pins.
+
 Before executing the test, start the *rfc2217* server with: ``python rfc2217_server.py -v`` *com-port*
 
 To see all data apply this [patch](https://github.com/mik3y/usb-serial-for-android/blob/master/test/rfc2217_server.diff) and use ``-v -v`` option.