diff --git a/opensim-standalone/Dockerfile-standalone b/opensim-standalone/Dockerfile-standalone
index 9a5a531..18359fd 100644
--- a/opensim-standalone/Dockerfile-standalone
+++ b/opensim-standalone/Dockerfile-standalone
@@ -20,53 +20,46 @@ RUN apt-get update \
         sqlite \
     && rm -rf /var/lib/apt/lists/*
 
-# Scripts that keep OpenSimulator running, make crash reports, clean up log files, etc
-COPY scripts/* /home/opensim/
-COPY vimrc /home/opensim/.vimrc
+# The simulator is run under the user name 'opensim'
+# (From https://stackoverflow.com/questions/27701930/add-user-to-docker-container)
+RUN adduser --disabled-password --gecos 'OpenSimulator user' opensim
 
-# Fetch the latest version of the OpenSimulator sources.
+USER opensim:opensim
+
+# Scripts that keep OpenSimulator running, make crash reports, clean up log files, etc
+COPY --chown=opensim:opensim scripts/* /home/opensim/
+COPY --chown=opensim:opensim vimrc /home/opensim/.vimrc
+
+# Fetch and build the latest version of the OpenSimulator sources.
+# THis includes a lot of steps so we can delete the sources and git files
+#    to make the resulting layer small.
 RUN cd /home/opensim \
     && git clone git://opensimulator.org/git/opensim \
-    && cp $OPENSIMDIR/bin/OpenSim.ini.example $OPENSIMDIR/bin/OpenSim.ini
+    && rm -rf $OPENSIMDIR/.git \
+    && cd $OPENSIMDIR \
+    && ./runprebuild.sh \
+    && msbuild \
+    && cd $OPENSIMDIR \
+    && rm -rf OpenSim
 
 # OpenSim.ini does an include of "config-include/Standalone.ini".
 #     so copy an empty version to nullfy the default configuration.
-COPY config-include/ $OPENSIMDIR/bin/config-include/
+COPY --chown=opensim:opensim config-include/ $OPENSIMDIR/bin/config-include/
 # Copy over any extra configuration files we're including
 RUN mkdir -p $OPENSIMDIR/bin/config
-COPY config/ $OPENSIMDIR/bin/config/
+COPY --chown=opensim:opensim config/ $OPENSIMDIR/bin/config/
+# Use the default, included configuration parameters
+RUN cp $OPENSIMDIR/bin/OpenSim.ini.example $OPENSIMDIR/bin/OpenSim.ini
 
 # Build OpenSimulator
 RUN cd $OPENSIMDIR \
     && ./runprebuild.sh \
     && msbuild
 
-# ============================================================================
-# 'slim' doesn't run OpenSimulator so it can't be used
-# FROM mono:5-slim
-FROM mono:5
+# Remove sources that are not needed for running
+RUN cd $OPENSIMDIR \
+    && rm -rf OpenSim
 
-ENV OPENSIMDIR=/home/opensim/opensim
-
-# Include required packages ('coreutils git vim' included for debugging)
-RUN apt-get update \
-    && apt-get install -y \
-        coreutils git vim \
-        procps \
-        screen \
-        ccrypt \
-        cron \
-        mysql-client \
-        sqlite \
-    && rm -rf /var/lib/apt/lists/*
-
-# The simulator is run under the user name 'opensim'
-# (From https://stackoverflow.com/questions/27701930/add-user-to-docker-container)
-RUN adduser --disabled-password --gecos 'OpenSimulator user' opensim
-
-COPY --from=built --chown=opensim:opensim /home/opensim/ /home/opensim
-
-USER opensim:opensim
 WORKDIR $OPENSIMDIR/bin
 ENTRYPOINT [ "/home/opensim/bootOpenSim.sh" ]