diff --git a/Dockerfile b/Dockerfile
index d8b83b9..58120f8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -43,7 +43,7 @@ ARG EXCLUDE_VARS="HOME PASSWORD RSTUDIO_VERSION BATCH_USER_CREATION"
 ARG R_HOME="/usr/local"
 # The 0*_ scripts cannot be used anymore
 # ADD 01_set_env.sh /etc/cont-init.d/01_set_env
-RUN for file in /var/run/s6/container_environment/* ; do sed -i "/^${file##*/}=/d" ${R_HOME}/etc/Renviron.site ; regex="(^| )${file##*/}($| )" ; if [ ! "$exclude_vars" =~ "$regex" ] ; then echo "${file##*/}=$(cat $file)" >> ${R_HOME}/etc/Renviron.site ; fi ; done
+RUN for file in /var/run/s6/container_environment/* ; do sed -i "/^${file##*/}=/d" ${R_HOME}/etc/Renviron.site ; regex="(^| )${file##*/}($| )" ; [[ $exclude_vars =~ $regex ]] && echo "${file##*/}=$(cat $file)" >> ${R_HOME}/etc/Renviron.site ; done
 
 # ADD 02_userconf.sh /etc/cont-init.d/02_userconf
 RUN mv -f /etc/rstudio/disable_auth_rserver.conf /etc/rstudio/rserver.conf
@@ -77,7 +77,7 @@ RUN chmod a+rx /usr/local/bin/fix-permissions
 RUN echo "auth requisite pam_deny.so" >> /etc/pam.d/su && \
     sed -i.bak -e 's/^%admin/#%admin/' /etc/sudoers && \
     sed -i.bak -e 's/^%sudo/#%sudo/' /etc/sudoers && \
-    userdel -r rstudio && \
+    userdel -r "${NB_USER}" && \
     useradd -l -m -s /bin/bash -N -u "${NB_UID}" "${NB_USER}" && \
     chmod g+w /etc/passwd && \
     fix-permissions "${HOME}"