diff --git a/.github/workflows/add-to-project.yml b/.github/workflows/add-to-project.yml
index b09bbee..c5f2f62 100644
--- a/.github/workflows/add-to-project.yml
+++ b/.github/workflows/add-to-project.yml
@@ -10,7 +10,7 @@ jobs:
     name: Add issue to project
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/add-to-project@v1.0.2
+      - uses: actions/add-to-project@244f685bbc3b7adfa8466e08b698b5577571133e # v1.0.2
         with:
           project-url: https://github.com/orgs/fluent/projects/4
           github-token: ${{ secrets.ADD_TO_PROJECT_PAT }}
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 62cab20..ea1cd2c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,21 +23,21 @@ jobs:
             dockerfile: Dockerfile.ruby34
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3.12.0
       - name: Build and push
         id: docker_build
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@10e90e3645eae34f1e60eeb005ba3a3d33f178e8 # v6.19.2
         with:
           file: test/docker/${{ matrix.target.dockerfile }}
   rubocop:
     runs-on: ubuntu-latest
     steps:
       -
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       -
-        uses: ruby/setup-ruby@v1
+        uses: ruby/setup-ruby@09a7688d3b55cf0e976497ff046b70949eeaccfd # v1.288.0
         with:
           bundler-cache: true
       -
diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
index 8c19f65..4d9c125 100644
--- a/.github/workflows/pr.yml
+++ b/.github/workflows/pr.yml
@@ -22,23 +22,23 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       -
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       -
         name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3.12.0
       -
         name: Build and push
         id: docker_build
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@10e90e3645eae34f1e60eeb005ba3a3d33f178e8 # v6.19.2
         with:
           file: test/docker/${{ matrix.target.dockerfile }}
   rubocop:
     runs-on: ubuntu-latest
     steps:
       -
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       -
-        uses: ruby/setup-ruby@v1
+        uses: ruby/setup-ruby@09a7688d3b55cf0e976497ff046b70949eeaccfd # v1.288.0
         with:
           bundler-cache: true
       -