diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index fc9314d..733acbb 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b # v4
       - uses: DeterminateSystems/flake-checker-action@4b90f9fc724969ff153fe1803460917c84fe00a3 # v5
       - uses: DeterminateSystems/nix-installer-action@main
       - uses: DeterminateSystems/magic-nix-cache-action@main