diff --git a/lazyDir/centos7.Dockerfile b/lazyDir/centos7.Dockerfile
index fb061ea..0381d2e 100644
--- a/lazyDir/centos7.Dockerfile
+++ b/lazyDir/centos7.Dockerfile
@@ -86,13 +86,10 @@
 
 # Enable SCLs for any later bash session
 # The script can also be sourced if the entry-point is overwritten
-RUN echo "#!/usr/bin/env bash" > "/usr/local/bin/withscl" \
-  && echo 'if ! [[ "${PATH}" =~ "${HOME}/bin" ]]; then export PATH=${PATH}:${HOME}/bin; fi' >> "/usr/local/bin/withscl" \
-  && echo 'while read SCL; do source scl_source enable ${SCL}; done < <(scl --list)' >> "/usr/local/bin/withscl" \
-  && echo 'if [ "$(basename "${0}")" == "$(basename ${BASH_SOURCE[0]})" ]; then exec "$@"; fi' >> "/usr/local/bin/withscl" \
-  && chmod 0755 "/usr/local/bin/withscl"
+COPY enable-scl.sh /usr/local/bin/enable-scl.sh
+RUN chmod 0755 /usr/local/bin/enable-scl.sh
 
-ENTRYPOINT [ "/usr/local/bin/withscl" ]
+ENTRYPOINT [ "/usr/local/bin/enable-scl.sh" ]
 
 # Configure desired timezone
 ENV TZ=Europe/Amsterdam
@@ -115,18 +112,20 @@
 USER ${user}
 WORKDIR /home/${user}
 
-# Install Fastlane
-RUN echo "gem: --no-document --user-install --bindir /home/android/bin" >> /home/${user}/.gemrc
-RUN echo "gempath: /home/${user}/.gem/ruby:/home/${user}/.bundle/gems/ruby/2.6.0:/opt/rh/rh-ruby26/root/usr/share/gems" >> .gemrc
-RUN /usr/local/bin/withscl gem install bundler --version `sed -n -r -e '/BUNDLED WITH/,$ { s/\s+([.0-9]+)/\1/ p }' Gemfile.lock`
-RUN /usr/local/bin/withscl bundle config --global path /home/${user}/.bundle/gems
-RUN /usr/local/bin/withscl bundle config --global bin /home/${user}/bin
-RUN /usr/local/bin/withscl bundle install && /usr/local/bin/withscl bundle clean
+# Install Fastlane for this user
+RUN source /usr/local/bin/enable-scl.sh \
+  && echo "gem: --no-document --user-install --bindir /home/android/bin" >> /home/${user}/.gemrc \
+  && echo "gempath: /home/${user}/.gem/ruby:/home/${user}/.bundle/gems/ruby/2.6.0:/opt/rh/rh-ruby26/root/usr/share/gems" >> .gemrc \
+  && gem install bundler --version `sed -n -r -e '/BUNDLED WITH/,$ { s/\s+([.0-9]+)/\1/ p }' Gemfile.lock` \
+  && bundle config --global path /home/${user}/.bundle/gems \
+  && bundle config --global bin /home/${user}/bin \
+  && bundle install && rm -rf /home/${user}/.bundle/cache
 
 # Prepare locales and other variables
 ARG locale=en_US.UTF-8
 ENV LANG "${locale}"
 ENV LC_ALL "${locale}"
+ENV USER ${user}
 
 # Get script directory from lazyLib at last to avoid warning w/o invalidating the cache 
 ARG dir=.
diff --git a/lazyDir/enable-scl.sh b/lazyDir/enable-scl.sh
new file mode 100755
index 0000000..6cbf23b
--- /dev/null
+++ b/lazyDir/enable-scl.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+# Configure bash behavior
+#set -o xtrace # to debug
+
+# Make sure home bin directory is in PATH 
+if ! [[ "${PATH}" =~ "${HOME}/bin" ]]; then
+  export PATH="${HOME}/bin:${PATH}"
+fi
+
+# Activate all Software collections - if any
+IFS=$'\n' SCLS=($(scl --list)) && test ${#SCLS[@]} -eq 0 || source scl_source enable "${SCLS[@]}"
+
+# Execute arguments as command if requested 
+if [ "$(basename "${0}")" == "$(basename ${BASH_SOURCE[0]})" -a ${#} -gt 0 ]; then
+	# Configure bash behavior
+	set -o errexit  # exit on failed command
+	set -o nounset  # exit on undeclared variables
+	set -o pipefail # exit on any failed command in pipes
+
+	# Expand arguments as command
+  exec "${@}"
+fi