diff --git a/webapp/Dockerfile b/webapp/Dockerfile
index 9dfb80c..b277248 100644
--- a/webapp/Dockerfile
+++ b/webapp/Dockerfile
@@ -19,6 +19,7 @@ apt-get clean
 rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* ~/.cache ~/.npm
 rm -rf ~/webapp-6.0.0.57.1049268-Ubuntu_20.04-all
 EOF
+# use envsubst in entrypoint script to convert config templates to actual config files
 WORKDIR /root
 EXPOSE 80
 VOLUME /var/lib/z-push