diff --git a/config/example-multi-mcu.cfg b/config/example-multi-mcu.cfg
index 144651c32..e2f2a0b37 100644
--- a/config/example-multi-mcu.cfg
+++ b/config/example-multi-mcu.cfg
@@ -9,17 +9,17 @@
 # micro-controllers on the printer. Typically, both the X and Y axes
 # are connected to the main micro-controller.
 [mcu]
-serial: /dev/ttyACM0
+serial: /dev/serial/by-path/platform-3f980000.usb-usb-0:1.2:1.0-port0
 pin_map: arduino
 
 # The "zboard" micro-controller will be used to control the Z axis.
 [mcu zboard]
-serial: /dev/ttyACM1
+serial: /dev/serial/by-path/platform-3f980000.usb-usb-0:1.3:1.0-port0
 pin_map: arduino
 
 # The "auxboard" micro-controller will be used to control the heaters.
 [mcu auxboard]
-serial: /dev/ttyACM2
+serial: /dev/serial/by-path/platform-3f980000.usb-usb-0:1.4:1.0-port0
 pin_map: arduino
 
 [stepper_x]
diff --git a/docs/FAQ.md b/docs/FAQ.md
index 351701cbb..d2fc3ccd9 100644
--- a/docs/FAQ.md
+++ b/docs/FAQ.md
@@ -38,7 +38,7 @@ The general way to find a USB serial port is to run `ls -l
 /dev/serial/by-id/` from an ssh terminal on the host machine. It will
 likely produce output similar to the following:
 ```
-lrwxrwxrwx 1 root root 13 Jan 3 22:15 usb-UltiMachine__ultimachine.com__RAMBo_12345678912345678912-if00 -> ../../ttyACM0
+lrwxrwxrwx 1 root root 13 Jun  1 21:12 usb-1a86_USB2.0-Serial-if00-port0 -> ../../ttyUSB0
 ```
 
 The name found in the above command is stable and it is possible to
@@ -46,18 +46,22 @@ use it in the config file and while flashing the micro-controller
 code. For example, a flash command might look similar to:
 ```
 sudo service klipper stop
-make flash FLASH_DEVICE=/dev/serial/by-id/usb-UltiMachine__ultimachine.com__RAMBo_12345678912345678912-if00
+make flash FLASH_DEVICE=/dev/serial/by-id/usb-1a86_USB2.0-Serial-if00-port0
 sudo service klipper start
 ```
 and the updated config might look like:
 ```
 [mcu]
-serial: /dev/serial/by-id/usb-UltiMachine__ultimachine.com__RAMBo_12345678912345678912-if00
+serial: /dev/serial/by-id/usb-1a86_USB2.0-Serial-if00-port0
 ```
 
 Be sure to copy-and-paste the name from the "ls" command that you ran
 above as the name will be different for each printer.
 
+If you are using multiple micro-controllers and they do not have
+unique ids (common on boards with a CH340 USB chip) then follow the
+directions above using the directory `/dev/serial/by-path/` instead.
+
 ### When the micro-controller restarts the device changes to /dev/ttyUSB1
 
 Follow the directions in the