diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index aef1068..89f1e90 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -5,7 +5,7 @@ jobs:
     name: runner & black formatter
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v6.0.2
       - uses: psf/black@stable
         with:
           black_args: ". --check"