diff --git a/test/e2e/bundle.test.ts b/test/e2e/bundle.test.ts
index 529044f..2d17d44 100644
--- a/test/e2e/bundle.test.ts
+++ b/test/e2e/bundle.test.ts
@@ -1,50 +1,10 @@
-import { readdirSync, readFileSync } from 'node:fs'
-import { isBuiltin } from 'node:module'
-import { join, relative } from 'node:path'
-import { fileURLToPath, pathToFileURL } from 'node:url'
-import { init, parse } from 'es-module-lexer'
-import { resolveModuleURL } from 'exsolve'
-import { expect, it } from 'vitest'
+import { fileURLToPath } from 'node:url'
+import { it } from 'vitest'
+import { expectSelfContainedBundle } from '../server-bundle'
 
 const serverDir = fileURLToPath(new URL('../../playground/.output/server/', import.meta.url))
 
-// Optional peers imported behind a try/catch, absent unless a site installs them.
-const OPTIONAL_IMPORTS = new Set([
-  // `@nuxtjs/mcp-toolkit` Code Mode.
-  'secure-exec',
-])
-
-/** The bundled chunks: the traced `node_modules/` are third-party files Nitro copied as they are. */
-function bundledFiles(): string[] {
-  return readdirSync(serverDir, { withFileTypes: true, recursive: true })
-    .filter((entry) => entry.isFile() && entry.name.endsWith('.mjs'))
-    .map((entry) => join(entry.parentPath, entry.name))
-    .filter((file) => !relative(serverDir, file).startsWith('node_modules'))
-}
-
 // A lazy chunk (a component, a route) only fails once requested, so the route crawl alone can miss it.
 it('every import in the server bundle resolves inside the build output', async () => {
-  await init()
-  const files = bundledFiles()
-  const broken: string[] = []
-  let checked = 0
-
-  for (const file of files) {
-    const [imports] = parse(readFileSync(file, 'utf8'))
-    for (const entry of imports) {
-      // `import.meta`, computed dynamic imports and template globs name no single module.
-      const specifier = entry.type === 'dynamic' && entry.glob ? undefined : entry.specifier
-      if (!specifier || isBuiltin(specifier) || OPTIONAL_IMPORTS.has(specifier)) continue
-      checked++
-      const resolved = resolveModuleURL(specifier, { from: pathToFileURL(file), try: true })
-      // Resolving into the repo's own `node_modules` works locally but not once deployed.
-      if (!resolved?.startsWith(pathToFileURL(serverDir).href)) {
-        broken.push(`${relative(serverDir, file)} imports ${specifier}`)
-      }
-    }
-  }
-
-  // Guards against a vacuous pass, e.g. the lexer reporting no specifiers after an API change.
-  expect(checked).toBeGreaterThan(files.length)
-  expect(broken).toEqual([])
+  await expectSelfContainedBundle(serverDir)
 })
diff --git a/test/server-bundle.ts b/test/server-bundle.ts
new file mode 100644
index 0000000..e6d2ff3
--- /dev/null
+++ b/test/server-bundle.ts
@@ -0,0 +1,48 @@
+import { readdirSync, readFileSync } from 'node:fs'
+import { isBuiltin } from 'node:module'
+import { join, relative } from 'node:path'
+import { pathToFileURL } from 'node:url'
+import { init, parse } from 'es-module-lexer'
+import { resolveModuleURL } from 'exsolve'
+import { expect } from 'vitest'
+
+// Optional peers imported behind a try/catch, absent unless a site installs them.
+const OPTIONAL_IMPORTS = new Set([
+  // `@nuxtjs/mcp-toolkit` Code Mode.
+  'secure-exec',
+])
+
+/** The bundled chunks: the traced `node_modules/` are third-party files Nitro copied as they are. */
+function bundledFiles(serverDir: string): string[] {
+  return readdirSync(serverDir, { withFileTypes: true, recursive: true })
+    .filter((entry) => entry.isFile() && entry.name.endsWith('.mjs'))
+    .map((entry) => join(entry.parentPath, entry.name))
+    .filter((file) => !relative(serverDir, file).startsWith('node_modules'))
+}
+
+/** Asserts every import in a Nitro server bundle resolves inside `serverDir`. */
+export async function expectSelfContainedBundle(serverDir: string) {
+  await init()
+  const files = bundledFiles(serverDir)
+  const broken: string[] = []
+  let checked = 0
+
+  for (const file of files) {
+    const [imports] = parse(readFileSync(file, 'utf8'))
+    for (const entry of imports) {
+      // `import.meta`, computed dynamic imports and template globs name no single module.
+      const specifier = entry.type === 'dynamic' && entry.glob ? undefined : entry.specifier
+      if (!specifier || isBuiltin(specifier) || OPTIONAL_IMPORTS.has(specifier)) continue
+      checked++
+      const resolved = resolveModuleURL(specifier, { from: pathToFileURL(file), try: true })
+      // Resolving into the repo's own `node_modules` works locally but not once deployed.
+      if (!resolved?.startsWith(pathToFileURL(serverDir).href)) {
+        broken.push(`${relative(serverDir, file)} imports ${specifier}`)
+      }
+    }
+  }
+
+  // Guards against a vacuous pass, e.g. the lexer reporting no specifiers after an API change.
+  expect(checked).toBeGreaterThan(files.length)
+  expect(broken).toEqual([])
+}
diff --git a/test/vercel/output.test.ts b/test/vercel/output.test.ts
index 0009b49..175534d 100644
--- a/test/vercel/output.test.ts
+++ b/test/vercel/output.test.ts
@@ -2,6 +2,7 @@ import { existsSync, lstatSync, readdirSync, readFileSync } from 'node:fs'
 import { join, relative } from 'node:path'
 import { fileURLToPath } from 'node:url'
 import { describe, expect, it } from 'vitest'
+import { expectSelfContainedBundle } from '../server-bundle'
 
 const outputDir = fileURLToPath(new URL('../../playground/.vercel/output/', import.meta.url))
 const functionsDir = join(outputDir, 'functions')
@@ -151,6 +152,11 @@ describe('server function', () => {
     expect(bytes / 1024 / 1024).toBeLessThan(MAX_FUNCTION_MB)
   })
 
+  // Vercel uploads the function directory alone, with its own traced `node_modules/`.
+  it('resolves every import inside the function', async () => {
+    await expectSelfContainedBundle(serverDir)
+  })
+
   // Without it a cold start walks the content repository on GitHub.
   it('bundles the content snapshot and its manifest, stamped with one commit', async () => {
     const snapshot = await readRawAsset<{ ref: string; items: Array<{ path: string }> }>('snapshot')