diff --git a/.github/workflows/make-pdfs.yml b/.github/workflows/make-pdfs.yml
index 4d2c61f..164b953 100644
--- a/.github/workflows/make-pdfs.yml
+++ b/.github/workflows/make-pdfs.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4.1.7
-    - uses: cachix/install-nix-action@V27
+    - uses: cachix/install-nix-action@v29
       with:
         nix_path: nixpkgs=channel:nixos-unstable
     - run: |