diff --git a/Dockerfile b/Dockerfile
index 4ee8cff..adb1462 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,11 +1,12 @@
 FROM node:11-stretch
 
-# copy config and rules, which change rarely
+# copy config, which changes rarely
 COPY docs/config-docker.yml /root/.salty-dog.yml
-COPY rules /rules
 
-# copy package and bundle, which change often
+# copy package first, to invalidate other layers when version changes
 COPY package.json /salty-dog/package.json
+
+COPY rules /salty-dog/rules
 COPY out/bundle.js /salty-dog/out/bundle.js
 
 ENTRYPOINT [ "node", "/salty-dog/out/bundle.js" ]
\ No newline at end of file