diff --git a/.github/workflows/nix.yml b/.github/workflows/nix.yml
index 699d924..1e87ce7 100644
--- a/.github/workflows/nix.yml
+++ b/.github/workflows/nix.yml
@@ -3,10 +3,10 @@ on:
   push:
 jobs:
   tests:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     - uses: actions/checkout@v2
-    - uses: cachix/install-nix-action@v8
+    - uses: cachix/install-nix-action@v12
     - uses: numtide/cachix-action@only-cache
       with:
         name: nix-community