diff --git a/src/node/build/build.ts b/src/node/build/build.ts
index 8464b2656c5a..f46d556c2def 100644
--- a/src/node/build/build.ts
+++ b/src/node/build/build.ts
@@ -6,7 +6,7 @@ import { renderPage } from './render'
 import { OutputChunk, OutputAsset } from 'rollup'
 
 export type BuildOptions = Pick<
-  ViteBuildOptions,
+  Partial<ViteBuildOptions>,
   | 'root'
   | 'rollupInputOptions'
   | 'rollupOutputOptions'
diff --git a/src/node/build/bundle.ts b/src/node/build/bundle.ts
index b3ef8d96c2f7..7cdabfe755d2 100644
--- a/src/node/build/bundle.ts
+++ b/src/node/build/bundle.ts
@@ -118,7 +118,7 @@ export async function bundle(
 
   // resolve options to pass to vite
   const { rollupInputOptions = {}, rollupOutputOptions = {} } = options
-  const viteOptions: ViteBuildOptions = {
+  const viteOptions: Partial<ViteBuildOptions> = {
     ...options,
     base: config.site.base,
     resolvers: [resolver],
@@ -153,5 +153,5 @@ export async function bundle(
     outDir: config.tempDir
   })
 
-  return [clientResult, serverResult, pageToHashMap]
+  return [clientResult[0], serverResult[0], pageToHashMap]
 }
diff --git a/src/node/markdownToVue.ts b/src/node/markdownToVue.ts
index f6715b1e349a..34594d60530e 100644
--- a/src/node/markdownToVue.ts
+++ b/src/node/markdownToVue.ts
@@ -63,6 +63,8 @@ export function createMarkdownToVueRenderFn(
 }
 
 const scriptRE = /<\/script>/
+const defaultExportRE = /((?:^|\n|;)\s*)export(\s*)default/
+const namedDefaultExportRE = /((?:^|\n|;)\s*)export(.+)as(\s*)default/
 
 function injectPageData(tags: string[], data: PageData) {
   const code = `\nexport const __pageData = ${JSON.stringify(
@@ -70,9 +72,14 @@ function injectPageData(tags: string[], data: PageData) {
   )}`
   const existingScriptIndex = tags.findIndex((tag) => scriptRE.test(tag))
   if (existingScriptIndex > -1) {
-    tags[existingScriptIndex] = tags[existingScriptIndex].replace(
+    const tagSrc = tags[existingScriptIndex]
+    // user has <script> tag inside markdown
+    // if it doesn't have export default it will error out on build
+    const hasDefaultExport =
+      defaultExportRE.test(tagSrc) || namedDefaultExportRE.test(tagSrc)
+    tags[existingScriptIndex] = tagSrc.replace(
       scriptRE,
-      code + `</script>`
+      code + (hasDefaultExport ? `` : `\nexport default{}\n`) + `</script>`
     )
   } else {
     tags.push(`<script>${code}\nexport default {}</script>`)