diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
new file mode 100644
index 0000000..679c3ac
--- /dev/null
+++ b/.github/CODEOWNERS
@@ -0,0 +1 @@
+*	@embulk/elastic-maintainers
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 1af6e5a..07f474a 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -9,50 +9,40 @@ jobs:
     strategy:
       fail-fast: false
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Set up OpenJDK 8
-        uses: actions/setup-java@v2
+        uses: actions/setup-java@v4
         with:
           java-version: 8
           distribution: "temurin"
           cache: "gradle"
-
       - name: Run elastisearch container
         run: docker-compose up -d
-
       - name: List containers
         run: docker-compose ps
-
       - name: Grant execute permission for gradlew
         run: chmod +x gradlew
-
       - name: Testing
         run: ./gradlew check --console rich --info
-
       - name: Check building
         run: ./gradlew gem --console rich --info
-
       - name: JaCoCo test report
         if: success()
         run: ./gradlew jacocoTestReport
-
       - name: Pack reports
         if: always()
         run: zip -9 -r -q reports.zip ./build/reports
-
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v4
         if: success()
         with:
           name: reports
           path: ./reports.zip
-
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v4
         if: success()
         with:
           name: gem
           path: ./pkg/*.gem
-
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v4
         if: success()
         with:
           name: jar
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index b5c7bda..e33ae75 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -11,13 +11,12 @@ jobs:
     strategy:
       fail-fast: true
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up OpenJDK 8
-      uses: actions/setup-java@v2
+      uses: actions/setup-java@v4
       with:
         java-version: 8
         distribution: "temurin"
-        cache: "gradle"
     - name: Publish
       run: |
         mkdir -p $HOME/.gem
@@ -26,7 +25,7 @@ jobs:
         printf -- "---\n:rubygems_api_key: ${RUBYGEMS_API_KEY}\n" > $HOME/.gem/credentials
         ./gradlew --stacktrace publishMavenPublicationToMavenCentralRepository gemPush
       env:
-        ORG_GRADLE_PROJECT_ossrhUsername: embulk
+        ORG_GRADLE_PROJECT_ossrhUsername: ${{ vars.OSSRH_USERNAME }}
         ORG_GRADLE_PROJECT_ossrhPassword: ${{ secrets.OSSRH_PASSWORD }}
         ORG_GRADLE_PROJECT_signingKey: ${{ secrets.GPG_PRIVATE_KEY_ARMOR }}
         ORG_GRADLE_PROJECT_signingPassword: ${{ secrets.GPG_PRIVATE_KEY_PASSWORD }}