diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 8936bb1a..1812ce55 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -13,7 +13,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: cachix/install-nix-action@v13
       with:
-        nix_path: nixpkgs=channel:nixos-unstable
+        nix_path: nixpkgs=channel:nixos-21.05
     - uses: cachix/cachix-action@v10
       with:
         name: nix-community