diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 615f8ae..ebb04bd 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
-      - uses: DeterminateSystems/determinate-nix-action@v3.17.0
+      - uses: DeterminateSystems/determinate-nix-action@v3.21.1
       - uses: DeterminateSystems/flakehub-cache-action@v3
       - run: nix build .#schemasonnet
 
@@ -21,6 +21,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
-      - uses: DeterminateSystems/determinate-nix-action@v3.17.0
+      - uses: DeterminateSystems/determinate-nix-action@v3.21.1
       - uses: DeterminateSystems/magic-nix-cache-action@v13
       - run: nix flake check -L --show-trace
diff --git a/.github/workflows/update.yaml b/.github/workflows/update.yaml
index 469d0e6..d60e7ff 100644
--- a/.github/workflows/update.yaml
+++ b/.github/workflows/update.yaml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
-      - uses: DeterminateSystems/determinate-nix-action@v3.17.0
+      - uses: DeterminateSystems/determinate-nix-action@v3.21.1
       - uses: DeterminateSystems/update-flake-lock@ff43f160ef7014ae1a1fd85699fb6a44f436135b
         with:
           pr-title: Update Nix flake inputs