diff --git a/image/prepare.sh b/image/prepare.sh
index a1c3524..3b8c27a 100755
--- a/image/prepare.sh
+++ b/image/prepare.sh
@@ -14,7 +14,8 @@ mkdir -p /etc/container_environment
 echo -n no > /etc/container_environment/INITRD
 
 ## Enable Ubuntu Universe and Multiverse.
-cp /build/sources.list /etc/apt/sources.list
+sed -i 's/^#\s*\(deb.*universe\)$/\1/g' /etc/apt/sources.list
+sed -i 's/^#\s*\(deb.*multiverse\)$/\1/g' /etc/apt/sources.list
 apt-get update
 
 ## Fix some issues with APT packages.
diff --git a/image/sources.list b/image/sources.list
deleted file mode 100644
index da73077..0000000
--- a/image/sources.list
+++ /dev/null
@@ -1,25 +0,0 @@
-deb http://archive.ubuntu.com/ubuntu precise main restricted
-deb-src http://archive.ubuntu.com/ubuntu precise main restricted
-
-deb http://archive.ubuntu.com/ubuntu precise-updates main restricted
-deb-src http://archive.ubuntu.com/ubuntu precise-updates main restricted
-
-deb http://archive.ubuntu.com/ubuntu precise universe
-deb-src http://archive.ubuntu.com/ubuntu precise universe
-deb http://archive.ubuntu.com/ubuntu precise-updates universe
-deb-src http://archive.ubuntu.com/ubuntu precise-updates universe
-
-deb http://archive.ubuntu.com/ubuntu precise multiverse
-deb-src http://archive.ubuntu.com/ubuntu precise multiverse
-deb http://archive.ubuntu.com/ubuntu precise-updates multiverse
-deb-src http://archive.ubuntu.com/ubuntu precise-updates multiverse
-
-deb http://archive.ubuntu.com/ubuntu precise-backports main restricted universe multiverse
-deb-src http://archive.ubuntu.com/ubuntu precise-backports main restricted universe multiverse
-
-deb http://archive.ubuntu.com/ubuntu precise-security main restricted
-deb-src http://archive.ubuntu.com/ubuntu precise-security main restricted
-deb http://archive.ubuntu.com/ubuntu precise-security universe
-deb-src http://archive.ubuntu.com/ubuntu precise-security universe
-deb http://archive.ubuntu.com/ubuntu precise-security multiverse
-deb-src http://archive.ubuntu.com/ubuntu precise-security multiverse