diff --git a/deploy/rails-prod-Dockerfile b/deploy/rails-prod-Dockerfile
index b8c9c83..90f448e 100644
--- a/deploy/rails-prod-Dockerfile
+++ b/deploy/rails-prod-Dockerfile
@@ -1,6 +1,6 @@
 FROM ruby:2.5.1
 
-HEALTHCHECK --start-period=30s curl --insecure https://127.0.0.1/
+HEALTHCHECK --start-period=30s CMD curl --insecure https://127.0.0.1/
 
 RUN apt-get -qq update \
   && DEBIAN_FRONTEND=noninteractive apt-get -qq upgrade -y \