diff --git a/deploy.sh b/deploy.sh
index f425fce..065eb2b 100755
--- a/deploy.sh
+++ b/deploy.sh
@@ -12,15 +12,25 @@ fi
 
 mode="${1:-switch}"
 host="${2:-nuc}"
-target="${3:-$host.c3h}"
+target="${3:-c3h@$host.c3h}"
+
+if ! [ -d "hosts/$host" ]
+then
+	echo "Host $host does not exist. Choose from:"
+	ls hosts
+	exit
+fi
 
 echo "deploying $host to $target"
 sleep 1
 
-sources=$(nix-build nix/sources-dir.nix --no-out-link)
+tmp=$(mktemp -d)
+trap 'rm -rf "$tmp"' EXIT
+sources="$tmp/sources"
+cp -r $(nix-build nix/sources-dir.nix --no-out-link) $tmp/sources
 
 set -x
-system_drv=$(nix-instantiate "<nixpkgs/nixos>" -I $sources -I "nixos-config=$PWD/hosts/$host/configuration.nix" | head -n1)
+system_drv=$(nix-instantiate "<nixpkgs/nixos>" -A config.system.build.toplevel -I $sources -I "nixos-config=$PWD/hosts/$host/configuration.nix")
 nix-copy-closure --to $target $system_drv
 system=$(ssh $target "nix-store --realise $system_drv")
 ssh $target "sudo nix-env -p /nix/var/nix/profiles/system -i $system && sudo /nix/var/nix/profiles/system/bin/switch-to-configuration $mode"