diff --git a/.forgejo/workflows/update.yml b/.forgejo/workflows/update.yml
index 4b704cb..82bfb9b 100644
--- a/.forgejo/workflows/update.yml
+++ b/.forgejo/workflows/update.yml
@@ -5,11 +5,10 @@ on:
     - cron: '0 2 * * *'
 jobs:
     lockfile:
-        runs-on: ubuntu-22.04
+        runs-on: docker
+        container.image: nixos/nix
         steps:
             - name: checkout
               uses: actions/checkout@v4
-            - name: Install Nix
-              uses: https://github.com/DeterminateSystems/nix-installer-action@main
             - name: Update flake.lock
               run: 'nix flake update; git add flake.lock; git commit -m "flake.lock: Update"; git push'