diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index a79bd46..d4e96fa 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -16,6 +16,6 @@ jobs:
     runs-on: ${{ matrix.platform }}
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
     - name: test
       run: make test