diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f24aa06..9b9eff4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -4,8 +4,8 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4.2.2
-      - uses: cachix/install-nix-action@v31
+      - uses: actions/checkout@v4.1.7
+      - uses: cachix/install-nix-action@V27
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       - run: nix flake check
diff --git a/.github/workflows/update.yml b/.github/workflows/update.yml
index 4d1cac6..4a47a62 100644
--- a/.github/workflows/update.yml
+++ b/.github/workflows/update.yml
@@ -7,8 +7,8 @@ jobs:
   update-sources:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4.2.2
-      - uses: cachix/install-nix-action@v31
+      - uses: actions/checkout@v4.1.7
+      - uses: cachix/install-nix-action@V27
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       - run: ./update