diff --git a/.github/workflows/update.yml b/.github/workflows/update.yml
index 94e73ca..8b05a8c 100644
--- a/.github/workflows/update.yml
+++ b/.github/workflows/update.yml
@@ -12,6 +12,7 @@ jobs:
       - name: Install Nix
         uses: cachix/install-nix-action@v18
         with:
+          nix_path: nixpkgs=channel:nixos-unstable
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
             trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= nixcache:8KKuGz95Pk4UJ5W/Ni+pN+v+LDTkMMFV4yrGmAYgkDg= hydra.nixos.org-1:CNHJZBh9K4tP3EKF6FkkgeVYsS3ohTl+oS0Qa8bezVs=