diff --git a/docker/Dockerfile b/docker/Dockerfile
index adb80a9..8189d5d 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -29,19 +29,15 @@ ENV DEBIAN_FRONTEND noninteractive
 
 # Update distro.
 RUN echo "deb http://ftp.us.debian.org/debian testing non-free contrib" >> /etc/apt/sources.list
-RUN echo "deb http://mirrors.fe.up.pt/ubuntu xenial main restricted universe multiverse" >> /etc/apt/sources.list
-RUN echo "deb http://mirrors.fe.up.pt/ubuntu xenial-updates main restricted universe multiverse" >> /etc/apt/sources.list
-RUN echo "deb http://mirrors.fe.up.pt/ubuntu xenial-backports main restricted universe multiverse" >> /etc/apt/sources.list
 RUN apt-get update
 RUN apt-get install -y gnupg2
+RUN apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 40976EAF437D05B5
 RUN apt-get install -y apt-utils
 RUN apt-get install -y gpgv
-RUN apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 40976EAF437D05B5
 RUN apt-get update -y
 RUN apt-get install -y apt-utils
 RUN apt-get dist-upgrade -y
-RUN apt-get install -y g++-5
-RUN apt-get install -y gcc-5
+RUN apt-get install -y bash-completion
 RUN apt-get install -y wget
 RUN apt-get install -y bzip2
 RUN apt-get install -y git
@@ -52,8 +48,3 @@ RUN apt-get install -y vim
 RUN apt-get install -y nasm
 RUN apt-get install -y build-essential
 RUN apt-get install -y make
-RUN apt-get install -y bison
-RUN apt-get install -y flex
-RUN apt-get install -y libssl-dev
-RUN apt-get install -y libncurses-dev
-RUN update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 60 --slave /usr/bin/g++ g++ /usr/bin/g++-5