diff --git a/default.nix b/default.nix
new file mode 100644
index 0000000..a28f333
--- /dev/null
+++ b/default.nix
@@ -0,0 +1 @@
+import <nixpkgs> { overlays = [ (import ./overlay.nix) ]; }
diff --git a/update.sh b/update.sh
new file mode 100755
index 0000000..8176049
--- /dev/null
+++ b/update.sh
@@ -0,0 +1,18 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p coreutils common-updater-scripts git
+
+tmpdir="$(mktemp -d)"
+git clone --bare --depth=1 --branch=mobile-shell https://gitlab.gnome.org/verdre/gnome-shell.git "$tmpdir"
+pushd "$tmpdir"
+new_version="unstable-$(git show -s --pretty='format:%cs')"
+commit_sha="$(git show -s --pretty='format:%H')"
+popd
+update-source-version "gnome.gnome-shell" --file=overlay.nix "$new_version" --rev="$commit_sha"
+
+tmpdir="$(mktemp -d)"
+git clone --bare --depth=1 --branch=mobile-shell https://gitlab.gnome.org/verdre/mutter.git "$tmpdir"
+pushd "$tmpdir"
+new_version="unstable-$(git show -s --pretty='format:%cs')"
+commit_sha="$(git show -s --pretty='format:%H')"
+popd
+update-source-version "gnome.mutter" --file=overlay.nix "$new_version" --rev="$commit_sha"