diff --git a/ci/build-arduino.sh b/ci/build-arduino.sh
index 7f84e16..f8f2665 100644
--- a/ci/build-arduino.sh
+++ b/ci/build-arduino.sh
@@ -58,5 +58,6 @@ for f in **/*.ino ; do
      echo $d
      cd $d
      arduino-cli compile -b esp32:esp32:esp32 *.ino 
+     arduino-cli compile --clean
      cd $dR
 done