diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index acfa11b..fc9314d 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -8,7 +8,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - uses: DeterminateSystems/flake-checker-action@v4
+      - uses: DeterminateSystems/flake-checker-action@4b90f9fc724969ff153fe1803460917c84fe00a3 # v5
       - uses: DeterminateSystems/nix-installer-action@main
       - uses: DeterminateSystems/magic-nix-cache-action@main
       - run: nix flake check --show-trace --accept-flake-config