diff --git a/rails-prod-Dockerfile b/rails-prod-Dockerfile
index e5b90a5..3c2716d 100644
--- a/rails-prod-Dockerfile
+++ b/rails-prod-Dockerfile
@@ -1,7 +1,7 @@
 FROM ruby:2.3.0
 
 
-RUN apt-get update
+RUN apt-get clean && apt-get update
 RUN apt-get -y upgrade
 
 RUN DEBIAN_FRONTEND=noninteractive apt-get -y install build-essential libssl-dev libyaml-dev libreadline-dev openssl curl git-core zlib1g-dev bison libxml2-dev libxslt1-dev libcurl4-openssl-dev libsqlite3-dev sqlite3 wget apache2 apt-transport-https nodejs nodejs-legacy npm mysql-client postfix