diff --git a/Dockerfile.agnos b/Dockerfile.agnos
index fe355e0..7b7830d 100644
--- a/Dockerfile.agnos
+++ b/Dockerfile.agnos
@@ -10,9 +10,7 @@ RUN mkdir -p /tmp/agnos
 # Stop on error
 RUN set -xe
 
-ENV USERNAME=comma
-ENV PASSWD=comma
-ENV HOST=comma
+ARG USERNAME=comma
 
 # Base system setup
 RUN echo "resolvconf resolvconf/linkify-resolvconf boolean false" | debconf-set-selections