diff --git a/.github/workflows/playwright.yml b/.github/workflows/playwright.yml
index bd28673..f266b8b 100644
--- a/.github/workflows/playwright.yml
+++ b/.github/workflows/playwright.yml
@@ -36,6 +36,10 @@ jobs:
         weed version
     - name: Install dependencies
       run: pnpm install --frozen-lockfile
+    - name: Build app and enforce bundle guard
+      run: |
+        pnpm build
+        pnpm build:bundle-guard
     - name: Verify ffprobe
       run: ffprobe -version
     - name: Install Playwright Browsers
diff --git a/next.config.ts b/next.config.ts
index 7beea83..b2952b3 100644
--- a/next.config.ts
+++ b/next.config.ts
@@ -1,10 +1,4 @@
 import type { NextConfig } from "next";
-import path from "node:path";
-import { createRequire } from "node:module";
-
-type DefinePluginCtor = new (defs: Record<string, string>) => unknown;
-const require = createRequire(import.meta.url);
-const { DefinePlugin } = require('webpack') as { DefinePlugin: DefinePluginCtor };
 
 const securityHeaders = [
   { key: 'X-Content-Type-Options', value: 'nosniff' },
@@ -21,11 +15,7 @@ const securityHeaders = [
   },
 ];
 
-const computeModeRaw = (process.env.COMPUTE_MODE || 'local').trim().toLowerCase();
-const computeMode = computeModeRaw === 'none' || computeModeRaw === 'worker' || computeModeRaw === 'local'
-  ? computeModeRaw
-  : 'local';
-const bundleWorkerCompute = computeMode === 'worker';
+const bundleWorkerCompute = true;
 const serverExternalPackages = [
   '@napi-rs/canvas',
   'better-sqlite3',
@@ -48,7 +38,7 @@ const nextConfig: NextConfig = {
       canvas: '@napi-rs/canvas',
     },
   },
-  transpilePackages: !bundleWorkerCompute ? ['@openreader/compute-core'] : [],
+  transpilePackages: [],
   serverExternalPackages,
   outputFileTracingIncludes: {
     '/api/audiobook': [
@@ -73,35 +63,14 @@ const nextConfig: NextConfig = {
   outputFileTracingExcludes: {
     '/*': [
       './docstore/**/*',
-      ...(bundleWorkerCompute
-        ? [
-            './node_modules/onnxruntime-node/**/*',
-            './node_modules/@huggingface/tokenizers/**/*',
-          ]
-        : []),
+      './node_modules/onnxruntime-node/**/*',
+      './node_modules/@huggingface/tokenizers/**/*',
     ],
   },
   webpack: (config, { isServer }) => {
     if (isServer && bundleWorkerCompute) {
-      config.plugins = config.plugins || [];
-      config.plugins.push(
-        new DefinePlugin({
-          __OPENREADER_COMPUTE_MODE__: JSON.stringify('worker'),
-        }),
-      );
-    }
-    if (isServer && bundleWorkerCompute) {
-      const workerComputeEntry = path.resolve(__dirname, 'src/lib/server/compute/index.worker.ts');
-      const computeIndexTs = path.resolve(__dirname, 'src/lib/server/compute/index.ts');
-      const computeIndexNoExt = path.resolve(__dirname, 'src/lib/server/compute/index');
-      const computeDir = path.resolve(__dirname, 'src/lib/server/compute');
       config.resolve.alias = {
         ...(config.resolve.alias || {}),
-        '@/lib/server/compute$': workerComputeEntry,
-        '@/lib/server/compute/index$': workerComputeEntry,
-        [`${computeIndexTs}$`]: workerComputeEntry,
-        [`${computeIndexNoExt}$`]: workerComputeEntry,
-        [`${computeDir}$`]: workerComputeEntry,
         '@openreader/compute-core/local-runtime$': false,
         'onnxruntime-node$': false,
         '@huggingface/tokenizers$': false,
diff --git a/package.json b/package.json
index 838d117..20f37f1 100644
--- a/package.json
+++ b/package.json
@@ -7,6 +7,7 @@
     "dev": "node scripts/openreader-entrypoint.mjs -- pnpm dev:raw",
     "dev:raw": "next dev --turbopack -p 3003",
     "build": "next build",
+    "build:bundle-guard": "node scripts/check-next-server-bundle.mjs",
     "start": "node scripts/openreader-entrypoint.mjs -- pnpm start:raw",
     "start:raw": "next start -p 3003",
     "lint": "next lint",
diff --git a/scripts/check-next-server-bundle.mjs b/scripts/check-next-server-bundle.mjs
new file mode 100644
index 0000000..9621cb4
--- /dev/null
+++ b/scripts/check-next-server-bundle.mjs
@@ -0,0 +1,50 @@
+import fs from 'node:fs';
+import path from 'node:path';
+
+const root = process.cwd();
+const serverDir = path.join(root, '.next', 'server');
+
+if (!fs.existsSync(serverDir)) {
+  console.error('[bundle-guard] Missing .next/server. Run `pnpm build` first.');
+  process.exit(1);
+}
+
+const forbidden = [
+  'onnxruntime-node',
+  '@huggingface/tokenizers',
+  '@openreader/compute-core/local-runtime',
+];
+
+const includeExt = new Set(['.js', '.mjs', '.cjs']);
+const failures = [];
+
+function walk(dir) {
+  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
+    const fullPath = path.join(dir, entry.name);
+    if (entry.isDirectory()) {
+      walk(fullPath);
+      continue;
+    }
+    if (!entry.isFile()) continue;
+    const ext = path.extname(entry.name).toLowerCase();
+    if (!includeExt.has(ext)) continue;
+    const text = fs.readFileSync(fullPath, 'utf8');
+    for (const pattern of forbidden) {
+      if (text.includes(pattern)) {
+        failures.push({ file: fullPath, pattern });
+      }
+    }
+  }
+}
+
+walk(serverDir);
+
+if (failures.length > 0) {
+  console.error('[bundle-guard] Forbidden compute deps detected in Next server bundle:');
+  for (const failure of failures) {
+    console.error(`- ${failure.pattern} in ${path.relative(root, failure.file)}`);
+  }
+  process.exit(1);
+}
+
+console.info('[bundle-guard] OK: no forbidden compute deps in .next/server');