diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 646bd26..c3577a4 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -9,7 +9,7 @@ jobs:
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
     - name: Set up Python
       uses: actions/setup-python@v5