diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5945ee3..fdf1966 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -20,10 +20,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - name: Set up Node.js
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
           # package.json's test script uses `node --test --test-isolation=none`,
           # which Node 20 doesn't support ("bad option") — match engines.node.