diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 992aa22..d103a35 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - uses: cachix/install-nix-action@V27
+    - uses: cachix/install-nix-action@V28
     - name: run tests
       run:
         nix develop -c 'tox'
diff --git a/.github/workflows/update-flake-lock.yml b/.github/workflows/update-flake-lock.yml
index 285923b..e52d02f 100644
--- a/.github/workflows/update-flake-lock.yml
+++ b/.github/workflows/update-flake-lock.yml
@@ -11,7 +11,7 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@V27
+        uses: cachix/install-nix-action@V28
       - name: Update flake.lock
         uses: DeterminateSystems/update-flake-lock@v24
         with: