diff --git a/tools/docker/Dockerfile b/tools/docker/Dockerfile
index ec65aaf..8a4ab94 100644
--- a/tools/docker/Dockerfile
+++ b/tools/docker/Dockerfile
@@ -21,5 +21,6 @@
 COPY gitconfig /home/$username/.gitconfig
 RUN chown $userid:$groupid /home/$username/.gitconfig
 ENV HOME=/home/$username
+ENV USER=$username
 
 ENTRYPOINT chroot --userspec=$(cat /root/username):$(cat /root/username) / /bin/bash -i