diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 43d9e62..10791b8 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -17,7 +17,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4
-    - uses: cachix/install-nix-action@v26
+    - uses: cachix/install-nix-action@V27
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
         extra_nix_config: |
diff --git a/.github/workflows/update-flake-lock.yml b/.github/workflows/update-flake-lock.yml
index 46e7137..8fcf264 100644
--- a/.github/workflows/update-flake-lock.yml
+++ b/.github/workflows/update-flake-lock.yml
@@ -13,7 +13,7 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v26
+        uses: cachix/install-nix-action@V27
         with:
           github_access_token: ${{ secrets.GITHUB_TOKEN }}
       - name: Update flake.lock