diff --git a/Dockerfile b/Dockerfile
index 2836cc8..3fb267d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -12,7 +12,7 @@ RUN apk --no-cache upgrade && \
         ruby-dev && \
     echo 'gem: --no-document' > /etc/gemrc && \
     gem install json foodcritic --no-rdoc --no-ri && \
-    gem cleanup \
+    gem cleanup && \
     apk del build-dependencies && \
     rm -rf /usr/lib/ruby/gems/*/cache/* \
         /var/cache/apk/* \