diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index fed1cba..3c70006 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,7 +15,7 @@ jobs:
     name: Lean Tests
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: leanprover/lean-action@v1
         with:
           build-args: "--wfail"
@@ -25,7 +25,7 @@ jobs:
     name: Nix Tests
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: cachix/install-nix-action@v31
         with:
           nix_path: nixpkgs=channel:nixos-unstable