diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 462d747..b0e9e00 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
       - uses: ruby/setup-ruby@v1
 
       - name: Configure Git