diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b5865b4..ecfca58 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@v25
+      - uses: cachix/install-nix-action@V27
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       - name: Free Disk Space
diff --git a/.github/workflows/update-flake.yml b/.github/workflows/update-flake.yml
index 36eed77..30df8dd 100644
--- a/.github/workflows/update-flake.yml
+++ b/.github/workflows/update-flake.yml
@@ -12,7 +12,7 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v27
+        uses: cachix/install-nix-action@V27
       - name: Update flake.lock
         uses: DeterminateSystems/update-flake-lock@v23
         with: