diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 3996953..ac60f01 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -12,6 +12,7 @@ jobs:
     - uses: actions/checkout@v2.4.0
     - uses: cachix/install-nix-action@v16
       with:
+        nix_path: nixpkgs=channel:nixos-unstable
         install_url: https://nixos-nix-install-tests.cachix.org/serve/vij683ly7sl95nnhb67bdjjfabclr85m/install
         install_options: '--tarball-url-prefix https://nixos-nix-install-tests.cachix.org/serve'
         extra_nix_config: |