diff --git a/.github/workflows/build-debug.yml b/.github/workflows/build-debug.yaml
similarity index 96%
rename from .github/workflows/build-debug.yml
rename to .github/workflows/build-debug.yaml
index b7728b7..3dd9970 100644
--- a/.github/workflows/build-debug.yml
+++ b/.github/workflows/build-debug.yaml
@@ -10,7 +10,9 @@ on:
 
 jobs:
   build-dotnet:
-    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    runs-on: ubuntu-24.04
     timeout-minutes: 10
     steps:
       - uses: Cysharp/Actions/.github/actions/checkout@main
@@ -25,7 +27,9 @@ jobs:
       max-parallel: 2
       matrix:
         unity: ["2022.3.39f1", "6000.0.12f1"] # Test with LTS
-    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    runs-on: ubuntu-24.04
     timeout-minutes: 30 # Unity build takes more than 20min.
     steps:
       - name: Load secrets
diff --git a/.github/workflows/build-docs.yml b/.github/workflows/build-docs.yaml
similarity index 91%
rename from .github/workflows/build-docs.yml
rename to .github/workflows/build-docs.yaml
index eb946f8..5bbd25e 100644
--- a/.github/workflows/build-docs.yml
+++ b/.github/workflows/build-docs.yaml
@@ -8,7 +8,10 @@ on:
 
 jobs:
   run-docfx:
-    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pages: write
+    runs-on: ubuntu-24.04
     timeout-minutes: 10
     steps:
       - uses: Cysharp/Actions/.github/actions/checkout@main
diff --git a/.github/workflows/build-release.yml b/.github/workflows/build-release.yaml
similarity index 94%
rename from .github/workflows/build-release.yml
rename to .github/workflows/build-release.yaml
index bf61a72..ffec70b 100644
--- a/.github/workflows/build-release.yml
+++ b/.github/workflows/build-release.yaml
@@ -14,6 +14,8 @@ on:
 
 jobs:
   update-packagejson:
+    permissions:
+      contents: write
     uses: Cysharp/Actions/.github/workflows/update-packagejson.yaml@main
     with:
       file-path: ./src/UniTask/Assets/Plugins/UniTask/package.json
@@ -22,7 +24,9 @@ jobs:
 
   build-dotnet:
     needs: [update-packagejson]
-    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    runs-on: ubuntu-24.04
     timeout-minutes: 10
     steps:
       - run: echo ${{ needs.update-packagejson.outputs.sha }}
@@ -46,7 +50,9 @@ jobs:
     strategy:
       matrix:
         unity: ["2022.3.39f1"]
-    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    runs-on: ubuntu-24.04
     timeout-minutes: 15
     steps:
       - name: Load secrets
@@ -92,6 +98,8 @@ jobs:
   # release
   create-release:
     needs: [update-packagejson, build-dotnet, build-unity]
+    permissions:
+      contents: write
     uses: Cysharp/Actions/.github/workflows/create-release.yaml@main
     with:
       commit-id: ${{ needs.update-packagejson.outputs.sha }}
@@ -105,6 +113,8 @@ jobs:
   cleanup:
     if: ${{ needs.update-packagejson.outputs.is-branch-created == 'true' }}
     needs: [update-packagejson, build-dotnet, build-unity]
+    permissions:
+      contents: write
     uses: Cysharp/Actions/.github/workflows/clean-packagejson-branch.yaml@main
     with:
       branch: ${{ needs.update-packagejson.outputs.branch-name }}
diff --git a/.github/workflows/prevent-github-change.yml b/.github/workflows/prevent-github-change.yaml
similarity index 84%
rename from .github/workflows/prevent-github-change.yml
rename to .github/workflows/prevent-github-change.yaml
index e654f3f..74573bb 100644
--- a/.github/workflows/prevent-github-change.yml
+++ b/.github/workflows/prevent-github-change.yaml
@@ -7,4 +7,6 @@ on:
 
 jobs:
   detect:
+    permissions:
+      contents: read
     uses: Cysharp/Actions/.github/workflows/prevent-github-change.yaml@main
diff --git a/.github/workflows/stale.yml b/.github/workflows/stale.yaml
similarity index 66%
rename from .github/workflows/stale.yml
rename to .github/workflows/stale.yaml
index b480c3e..c333a85 100644
--- a/.github/workflows/stale.yml
+++ b/.github/workflows/stale.yaml
@@ -7,4 +7,8 @@ on:
 
 jobs:
   stale:
+    permissions:
+      contents: read
+      pull-requests: write
+      issues: write
     uses: Cysharp/Actions/.github/workflows/stale-issue.yaml@main
diff --git a/.github/workflows/toc.yml b/.github/workflows/toc.yaml
similarity index 82%
rename from .github/workflows/toc.yml
rename to .github/workflows/toc.yaml
index 77e0c74..9f77f93 100644
--- a/.github/workflows/toc.yml
+++ b/.github/workflows/toc.yaml
@@ -6,8 +6,9 @@ on:
       - 'README.md'
 
 jobs:
-  generateTOC:
-    name: TOC Generator
+  toc:
+    permissions:
+      contents: write
     uses: Cysharp/Actions/.github/workflows/toc-generator.yaml@main
     with:
       TOC_TITLE: "## Table of Contents"