diff --git a/Dockerfile b/Dockerfile
index 3002255..86fc949 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,7 +9,7 @@ ARG ArduinoDownloadUrl=https://github.com/arduino/arduino-cli/releases/download/
 ARG ArduinoPackage=arduino-cli_0.29.0_Linux_64bit.tar.gz
 ARG ArduinoUID="1000"
 ARG ArduinoGID="1000"
-ENV USER arduino
+ARG USER="arduino"
 
 RUN \
   apt update && \