diff --git a/scripts/postinstall.sh b/scripts/postinstall.sh
index bdeee98..289aa7d 100755
--- a/scripts/postinstall.sh
+++ b/scripts/postinstall.sh
@@ -3,8 +3,6 @@
 set -e
 
 # Update and initialize our new configuration
-nix-channel --remove nixos
-nix-channel --add http://nixos.org/channels/nixos-unstable nixos
 nixos-rebuild switch --upgrade
 
 # Cleanup any previous generations and delete old packa
diff --git a/template.json b/template.json
index 2575ce9..110b376 100644
--- a/template.json
+++ b/template.json
@@ -22,14 +22,18 @@
       "guest_additions_mode": "disable",
       "guest_os_type": "Linux_64",
       "http_directory": "nixos",
-      "iso_checksum": "e6193d70d283d05795cb07422689d1cd",
+      "iso_checksum": "48395b4bd21675703c87cfae1feb68ed",
       "iso_checksum_type": "md5",
-      "iso_url": "http://releases.nixos.org/nixos/13.10/nixos-13.10.35608.1e7192a/nixos-minimal-13.10.35608.1e7192a-x86_64-linux.iso",
+      "iso_url": "http://releases.nixos.org/nixos/unstable/nixos-14.02pre38596.1dd0e05/nixos-minimal-14.02pre38596.1dd0e05-x86_64-linux.iso",
       "shutdown_command": "sudo shutdown -h now",
       "ssh_username": "root",
       "ssh_key_path": "keys/install.key",
       "ssh_wait_timeout": "10m",
-      "virtualbox_version_file": ".vbox_version"
+      "virtualbox_version_file": ".vbox_version",
+      "vboxmanage": [
+        ["modifyvm", "{{.Name}}", "--memory", "2048"],
+        ["modifyvm", "{{.Name}}", "--cpus", "2"]
+      ]
     }
   ],
   "provisioners": [