diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 8c5c4d90..ceb64f9e 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -33,13 +33,16 @@ jobs:
           # See: https://travis-ci.org/github/felis/USB_Host_Shield_2.0/jobs/743787235
           if [[ "${{ matrix.example }}" != *"bidirectional_converter" ]]; then TEENSY35="--board=teensy35"; TEENSY36="--board=teensy36"; TEENSY40="--board=teensy40"; TEENSY41="--board=teensy41"; fi
 
-          pio ci --lib="." $UNO --board=genuino101 --board=teensylc $TEENSY40 $TEENSY41 --board=esp12e --board=nodemcu --board=esp32dev --board=adafruit_feather_nrf52840
+          pio ci --lib="." $UNO --board=genuino101 --board=teensylc $TEENSY40 $TEENSY41 --board=esp12e --board=nodemcu --board=esp32dev
 
           # Teensy 3.x depends on the SPI4Teensy3 library: https://platformio.org/lib/show/417/SPI4Teensy3
           pio ci --lib="." --board=teensy30 --board=teensy31 $TEENSY35 $TEENSY36 --project-option="lib_deps=SPI4Teensy3"
 
           # Workaround https://github.com/arduino/ArduinoCore-sam/issues/69
           pio ci --lib="." --board=due --project-option="build_flags=-Wno-misleading-indentation"
+
+          # Workaround "warning: comparison between signed and unsigned integer expressions" in the Arduino core
+          pio ci --lib="." --board=adafruit_feather_nrf52840 --project-option="build_flags=-Wno-sign-compare"
         env:
           PLATFORMIO_CI_SRC: ${{ matrix.example }}
           PLATFORMIO_BUILD_FLAGS: -DWIICAMERA -DDEBUG_USB_HOST -Wall -Werror