diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 3053a30..cfc65d1 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -38,4 +38,4 @@ jobs:
           token: ${{ secrets.ATTIC_TOKEN }}
 
       - name: Build Nix Package
-        run: nix build -f test.nix
+        run: nix build -f test.nix -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixpkgs-unstable.tar.gz --show-trace