diff --git a/Dockerfile b/Dockerfile
index 96a22e99..68a16f47 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,9 @@
 FROM ubuntu:14.04
 
-RUN apt-get update && apt-get -y upgrade && apt-get -y install wget netcat
+RUN apt-get update && apt-get install -y \
+	wget \
+	netcat \
+	&& rm -rf /var/lib/apt/lists/*
 RUN mkdir -p /mattermost/data
 
 RUN touch /etc/init/mattermost.conf