diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cc738d2..ce0cd7d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,6 +2,10 @@ name: test
 
 on: [pull_request]
 
+permissions:
+  contents: read
+  pull-requests: read
+
 jobs:
   test:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/initiate_release.yml b/.github/workflows/initiate_release.yml
index 0ca047a..685a84e 100644
--- a/.github/workflows/initiate_release.yml
+++ b/.github/workflows/initiate_release.yml
@@ -7,6 +7,10 @@ on:
         description: "The new version number with 'v' prefix. Example: v1.40.1"
         required: true
 
+permissions:
+  contents: write
+  pull-requests: write
+
 jobs:
   init_release:
     name: 🚀 Create release PR
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 3b1ac57..57cf768 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -6,6 +6,10 @@ on:
     branches:
       - master
 
+permissions:
+  contents: read
+  pull-requests: read
+
 jobs:
   Release:
     name: 🚀 Release
diff --git a/.github/workflows/reviewdog.yml b/.github/workflows/reviewdog.yml
index ca9efc1..3f2a17c 100644
--- a/.github/workflows/reviewdog.yml
+++ b/.github/workflows/reviewdog.yml
@@ -6,6 +6,10 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref }}
   cancel-in-progress: true
 
+permissions:
+  contents: read
+  pull-requests: read
+
 jobs:
   rubocop:
     name: 🐶 Reviewdog
diff --git a/.github/workflows/scheduled_test.yml b/.github/workflows/scheduled_test.yml
index 517ddfa..960e38d 100644
--- a/.github/workflows/scheduled_test.yml
+++ b/.github/workflows/scheduled_test.yml
@@ -6,6 +6,10 @@ on:
     # Monday at 9:00 UTC
     - cron: '0 9 * * 1'
 
+permissions:
+  contents: read
+  pull-requests: write
+
 jobs:
   test:
     runs-on: ubuntu-latest