diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
index 80eb360e..b5946af1 100644
--- a/.github/CODEOWNERS
+++ b/.github/CODEOWNERS
@@ -1,2 +1,3 @@
 * @t-horikawa @ban-nobuhiro
 
+/.github/ @project-tsurugi/ci-maintainers
\ No newline at end of file
diff --git a/.github/workflows/ci-build.yml b/.github/workflows/ci-build.yml
index 5c0e0362..0db39a1e 100644
--- a/.github/workflows/ci-build.yml
+++ b/.github/workflows/ci-build.yml
@@ -13,10 +13,7 @@ jobs:
       checks: write
     timeout-minutes: 30
     container:
-      image: ghcr.io/project-tsurugi/oltp-sandbox:${{ matrix.os }}
-      credentials:
-        username: ${{ github.repository_owner }}
-        password: ${{ secrets.GHCR_PAT }}
+      image: ghcr.io/project-tsurugi/tsurugi-ci:${{ matrix.os }}
       volumes:
         - ${{ vars.ccache_dir }}:${{ vars.ccache_dir }}
     defaults:
@@ -60,10 +57,7 @@ jobs:
       checks: write
     timeout-minutes: 30
     container:
-      image: ghcr.io/project-tsurugi/oltp-sandbox:ubuntu-22.04
-      credentials:
-        username: ${{ github.repository_owner }}
-        password: ${{ secrets.GHCR_PAT }}
+      image: ghcr.io/project-tsurugi/tsurugi-ci:ubuntu-22.04
       volumes:
         - ${{ vars.ccache_dir }}:${{ vars.ccache_dir }}
     defaults: