diff --git a/Dockerfile b/Dockerfile
index 8cf17129b4948b98ddb1736d80ac59b8ed44d964..b7cbbbe6378901e3e9bb341dc4ebe4205eea49d1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -16,4 +16,5 @@ USER nobody
 CMD [ "supersonic", "/crontab" ]
 HEALTHCHECK CMD pgrep supersonic
 RUN supersonic -test /crontab
+ONBUILD COPY crontab /crontab
 ONBUILD RUN supersonic -test /crontab
diff --git a/README.md b/README.md
index d0d9f87a1dda668e4cfb15c1501ed47ab529f884..83ebfec554669f9ab7ffffc7a3622645b36c50a5 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,6 @@ like so:
 ```
 FROM registry.shore.co.il/cron
 RUN apk add --update --no-cache aws-cli
-COPY crontab /crontab
 COPY script /usr/local/bin/
 ```