diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 50d9049..82c79e7 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,6 +8,8 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - uses: cachix/install-nix-action@v12
+      with:
+        nix_path: nixpkgs=channel:nixos-unstable
     - name: Show nixpkgs version
       run: nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
     - run: ./tests/run.py