diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b02eb3b..078238a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,7 +39,7 @@ jobs:
           echo "rev=$(git rev-parse --short HEAD)" >> "$GITHUB_OUTPUT"
 
       - name: Install Nix
-        uses: cachix/install-nix-action@v27
+        uses: cachix/install-nix-action@V27
 
       - name: Format changes
         run: |
diff --git a/.github/workflows/website.yml b/.github/workflows/website.yml
index 020d7fe..01cd2db 100644
--- a/.github/workflows/website.yml
+++ b/.github/workflows/website.yml
@@ -17,7 +17,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install Nix
-        uses: cachix/install-nix-action@v26
+        uses: cachix/install-nix-action@V27
 
       - name: Setup cache
         uses: DeterminateSystems/magic-nix-cache-action@v6