diff --git a/.github/workflows/maintenance-cache-wipe.yml b/.github/workflows/maintenance-cache-wipe.yml
index 2871734..e3f7064 100644
--- a/.github/workflows/maintenance-cache-wipe.yml
+++ b/.github/workflows/maintenance-cache-wipe.yml
@@ -10,4 +10,4 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: easimon/wipe-cache@v2
+      - uses: easimon/wipe-cache@e7ab82e64c328fd39c2e96933d426cd72ac2beba # v2
diff --git a/.github/workflows/maintenance-workflow-cleanup.yml b/.github/workflows/maintenance-workflow-cleanup.yml
index dd4b060..765afac 100644
--- a/.github/workflows/maintenance-workflow-cleanup.yml
+++ b/.github/workflows/maintenance-workflow-cleanup.yml
@@ -9,7 +9,7 @@ jobs:
   delete-workflow-runs:
     runs-on: ubuntu-latest
     steps:
-      - uses: Mattraks/delete-workflow-runs@v2
+      - uses: Mattraks/delete-workflow-runs@b3018382ca039b53d238908238bd35d1fb14f8ee # v2
         with:
           token: ${{ github.token }}
           repository: ${{ github.repository }}
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index cc65311..d08f9f9 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -22,7 +22,7 @@ jobs:
       BUNDLE_WITHOUT: development test
 
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - uses: ruby/setup-ruby@v1
         with:
@@ -31,7 +31,7 @@ jobs:
 
       - uses: rubygems/release-gem@v1
 
-      - uses: taiki-e/create-gh-release-action@v1
+      - uses: taiki-e/create-gh-release-action@c5baa0b5dc700cf06439d87935e130220a6882d9 # v1
         with:
           changelog: CHANGELOG.md
           draft: true
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ebaf8cf..53b951e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -28,7 +28,7 @@ jobs:
       BUNDLE_WITHOUT: development
 
     steps:
-      - uses: actions/checkout@master
+      - uses: actions/checkout@61b9e3751b92087fd0b06925ba6dd6314e06f089 # master
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
@@ -49,7 +49,7 @@ jobs:
       BUNDLE_WITHOUT: test
 
     steps:
-      - uses: actions/checkout@master
+      - uses: actions/checkout@61b9e3751b92087fd0b06925ba6dd6314e06f089 # master
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: "4.0.2"