diff --git a/.github/workflows/doc.yaml b/.github/workflows/doc.yaml
index e73e30d..68b2fa6 100644
--- a/.github/workflows/doc.yaml
+++ b/.github/workflows/doc.yaml
@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@v26
+      - uses: cachix/install-nix-action@V27
         with:
           extra_nix_config: |
             accept-flake-config = true
diff --git a/.github/workflows/flake-updates.yml b/.github/workflows/flake-updates.yml
index 16f2e3e..6749ce1 100644
--- a/.github/workflows/flake-updates.yml
+++ b/.github/workflows/flake-updates.yml
@@ -9,7 +9,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v26
+        uses: cachix/install-nix-action@V27
         with:
           extra_nix_config: |
             experimental-features = nix-command flakes