diff --git a/.github/workflows/e2e-test.yml b/.github/workflows/e2e-test.yml
index 4b5a89ada9..b8fa95cf73 100644
--- a/.github/workflows/e2e-test.yml
+++ b/.github/workflows/e2e-test.yml
@@ -246,6 +246,10 @@ jobs:
               vp run type-check:tsgo
               vp run build
               vp run test navigation-utils.test.ts real-browser-flicker.test.tsx workflow-parallel-limit.test.tsx
+          - name: viteplus-ws-repro
+            node-version: 24
+            command: |
+              vp test run
         exclude:
           # frm-stack uses Docker (testcontainers) which doesn't work the same way on Windows
           - os: windows-latest
diff --git a/ecosystem-ci/patch-project.ts b/ecosystem-ci/patch-project.ts
index 7b3350c666..9215eae5dd 100644
--- a/ecosystem-ci/patch-project.ts
+++ b/ecosystem-ci/patch-project.ts
@@ -21,6 +21,18 @@ const cwd = directory ? join(repoRoot, directory) : repoRoot;
 // run vp migrate
 const cli = process.env.VITE_PLUS_CLI_BIN ?? 'vp';
 
+// Projects that already have vite-plus need it removed before migration so
+// vp migrate treats them as fresh and applies tgz overrides. Without this,
+// vp migrate detects "already using Vite+" and skips override injection.
+const forceFreshMigration = 'forceFreshMigration' in repoConfig && repoConfig.forceFreshMigration;
+if (forceFreshMigration) {
+  const pkgPath = join(cwd, 'package.json');
+  const pkg = JSON.parse(await readFile(pkgPath, 'utf-8'));
+  delete pkg.devDependencies?.['vite-plus'];
+  delete pkg.dependencies?.['vite-plus'];
+  await writeFile(pkgPath, JSON.stringify(pkg, null, 2) + '\n', 'utf-8');
+}
+
 if (project === 'rollipop') {
   const oxfmtrc = await readFile(join(repoRoot, '.oxfmtrc.json'), 'utf-8');
   await writeFile(
diff --git a/ecosystem-ci/repo.json b/ecosystem-ci/repo.json
index 7a64745f08..e1aa9fc242 100644
--- a/ecosystem-ci/repo.json
+++ b/ecosystem-ci/repo.json
@@ -54,5 +54,11 @@
     "repository": "https://github.com/fengmk2/vite-vue-vercel.git",
     "branch": "main",
     "hash": "f2bf9fc40880c6a80f5d89bff70641c2eeaf77ef"
+  },
+  "viteplus-ws-repro": {
+    "repository": "https://github.com/Charles5277/viteplus-ws-repro.git",
+    "branch": "main",
+    "hash": "451925ad7c07750a23de1d6ed454825d0eb14092",
+    "forceFreshMigration": true
   }
 }
diff --git a/packages/test/build.ts b/packages/test/build.ts
index 8def7e6465..4ed27b0039 100644
--- a/packages/test/build.ts
+++ b/packages/test/build.ts
@@ -302,9 +302,18 @@ async function mergePackageJson(pluginExports: Array<{ exportPath: string; shimF
     // browser-provider exports. Browser code uses index.js which is safe.
     // This separation prevents Node.js-only code (like __vite__injectQuery) from being
     // loaded in the browser, which would cause "Identifier already declared" errors.
+    //
+    // IMPORTANT: The 'browser' condition must come BEFORE 'node' because vitest passes
+    // custom --conditions (like 'browser') to worker processes when frameworks like Nuxt
+    // set edge/cloudflare presets. Without the 'browser' condition here, Node.js would
+    // match 'node' first, loading index-node.js which imports @vitest/browser/index.js,
+    // which imports 'ws'. With --conditions browser active, 'ws' resolves to its browser
+    // stub (ws/browser.js) that doesn't export WebSocketServer, causing a SyntaxError.
+    // See: https://github.com/voidzero-dev/vite-plus/issues/831
     if (destPkg.exports['.'] && destPkg.exports['.'].import) {
       destPkg.exports['.'].import = {
         types: destPkg.exports['.'].import.types,
+        browser: destPkg.exports['.'].import.default,
         node: './dist/index-node.js',
         default: destPkg.exports['.'].import.default,
       };
diff --git a/packages/test/package.json b/packages/test/package.json
index 5d2c8d0641..6a96280eef 100644
--- a/packages/test/package.json
+++ b/packages/test/package.json
@@ -37,6 +37,7 @@
     ".": {
       "import": {
         "types": "./dist/index.d.ts",
+        "browser": "./dist/index.js",
         "node": "./dist/index-node.js",
         "default": "./dist/index.js"
       },