diff --git a/.github/workflows/test-pnpm-v11.yml b/.github/workflows/test-pnpm-v11.yml
new file mode 100644
index 00000000..2768b339
--- /dev/null
+++ b/.github/workflows/test-pnpm-v11.yml
@@ -0,0 +1,38 @@
+name: Test pnpm v11 upgrade
+on:
+  push:
+    branches: [feat/upgrade-pnpm-v11]
+  pull_request:
+    branches: [main]
+    paths:
+      - '.github/workflows/test-pnpm-v11.yml'
+      - 'package.json'
+      - 'pnpm-lock.yaml'
+
+jobs:
+  test-pnpm-v11:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: web/site
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: pnpm/action-setup@v6
+        with:
+          version: latest-11
+
+      - uses: actions/setup-node@v6
+        with:
+          node-version: 24
+          cache: pnpm
+          cache-dependency-path: web/site/pnpm-lock.yaml
+
+      - name: Install dependencies
+        run: pnpm install
+
+      - name: Build
+        run: pnpm build
+
+      - name: Report pnpm version
+        run: pnpm --version
diff --git a/web/site/package.json b/web/site/package.json
index f670e55b..cc2dc96e 100644
--- a/web/site/package.json
+++ b/web/site/package.json
@@ -53,5 +53,5 @@
     "firebase-functions": "^4.9.0",
     "vuefire": "^3.1.24"
   },
-  "packageManager": "pnpm@10.10.0"
-}
+  "packageManager": "pnpm@11.9.0"
+}
\ No newline at end of file