diff --git a/packages/compiler-sfc/src/rewriteDefault.ts b/packages/compiler-sfc/src/rewriteDefault.ts
index ced9f56d8a9..e61cf691bba 100644
--- a/packages/compiler-sfc/src/rewriteDefault.ts
+++ b/packages/compiler-sfc/src/rewriteDefault.ts
@@ -42,7 +42,12 @@ export function rewriteDefault(
   }).program.body
   ast.forEach(node => {
     if (node.type === 'ExportDefaultDeclaration') {
-      s.overwrite(node.start!, node.declaration.start!, `const ${as} = `)
+      if (node.declaration.type === 'ClassDeclaration') {
+        s.overwrite(node.start!, node.declaration.id.start!, `class `)
+        s.append(`\nconst ${as} = ${node.declaration.id.name}`)
+      } else {
+        s.overwrite(node.start!, node.declaration.start!, `const ${as} = `)
+      }
     }
     if (node.type === 'ExportNamedDeclaration') {
       for (const specifier of node.specifiers) {
diff --git a/packages/compiler-sfc/test/rewriteDefault.spec.ts b/packages/compiler-sfc/test/rewriteDefault.spec.ts
new file mode 100644
index 00000000000..9fb4c64bbb3
--- /dev/null
+++ b/packages/compiler-sfc/test/rewriteDefault.spec.ts
@@ -0,0 +1,245 @@
+import { rewriteDefault } from '../src'
+
+describe('compiler sfc: rewriteDefault', () => {
+  test('without export default', () => {
+    expect(rewriteDefault(`export  a = {}`, 'script')).toMatchInlineSnapshot(`
+      "export  a = {}
+      const script = {}"
+    `)
+  })
+
+  test('rewrite export default', () => {
+    expect(
+      rewriteDefault(`export  default {}`, 'script')
+    ).toMatchInlineSnapshot(`"const script = {}"`)
+  })
+
+  test('rewrite export named default', () => {
+    expect(
+      rewriteDefault(
+        `const a = 1 \n export { a as b, a as default, a as c}`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+      "const a = 1 
+       export { a as b,  a as c}
+      const script = a"
+    `)
+
+    expect(
+      rewriteDefault(
+        `const a = 1 \n export { a as b, a as default    , a as c}`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+      "const a = 1 
+       export { a as b,  a as c}
+      const script = a"
+    `)
+  })
+
+  test('w/ comments', async () => {
+    expect(rewriteDefault(`// export default\nexport default {}`, 'script'))
+      .toMatchInlineSnapshot(`
+      "// export default
+      const script = {}"
+    `)
+  })
+
+  test('export named default multiline', () => {
+    expect(
+      rewriteDefault(`let App = {}\n export {\nApp as default\n}`, '_sfc_main')
+    ).toMatchInlineSnapshot(`
+      "let App = {}
+       export {
+      
+      }
+      const _sfc_main = App"
+    `)
+  })
+
+  test('export named default multiline /w comments', () => {
+    expect(
+      rewriteDefault(
+        `const a = 1 \n export {\n a as b,\n a as default,\n a as c}\n` +
+          `// export { myFunction as default }`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+      "const a = 1 
+       export {
+       a as b,
+       
+       a as c}
+      // export { myFunction as default }
+      const script = a"
+    `)
+
+    expect(
+      rewriteDefault(
+        `const a = 1 \n export {\n a as b,\n a as default      ,\n a as c}\n` +
+          `// export { myFunction as default }`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+      "const a = 1 
+       export {
+       a as b,
+       
+       a as c}
+      // export { myFunction as default }
+      const script = a"
+    `)
+  })
+
+  test(`export { default } from '...'`, async () => {
+    expect(
+      rewriteDefault(`export { default, foo } from './index.js'`, 'script')
+    ).toMatchInlineSnapshot(`
+    "import { default as __VUE_DEFAULT__ } from './index.js'
+    export {  foo } from './index.js'
+    const script = __VUE_DEFAULT__"
+    `)
+
+    expect(
+      rewriteDefault(`export { default    , foo } from './index.js'`, 'script')
+    ).toMatchInlineSnapshot(`
+    "import { default as __VUE_DEFAULT__ } from './index.js'
+    export {  foo } from './index.js'
+    const script = __VUE_DEFAULT__"
+    `)
+
+    expect(
+      rewriteDefault(`export { foo,   default } from './index.js'`, 'script')
+    ).toMatchInlineSnapshot(`
+    "import { default as __VUE_DEFAULT__ } from './index.js'
+    export { foo,    } from './index.js'
+    const script = __VUE_DEFAULT__"
+    `)
+
+    expect(
+      rewriteDefault(
+        `export { foo as default, bar } from './index.js'`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+    "import { foo } from './index.js'
+    export {  bar } from './index.js'
+    const script = foo"
+    `)
+
+    expect(
+      rewriteDefault(
+        `export { foo as default     , bar } from './index.js'`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+    "import { foo } from './index.js'
+    export {  bar } from './index.js'
+    const script = foo"
+    `)
+
+    expect(
+      rewriteDefault(
+        `export { bar,   foo as default } from './index.js'`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+    "import { foo } from './index.js'
+    export { bar,    } from './index.js'
+    const script = foo"
+    `)
+  })
+
+  test('export default class', async () => {
+    expect(rewriteDefault(`export default class Foo {}`, 'script'))
+      .toMatchInlineSnapshot(`
+      "class Foo {}
+      const script = Foo"
+    `)
+  })
+
+  test('export default class w/ comments', async () => {
+    expect(
+      rewriteDefault(`// export default\nexport default class Foo {}`, 'script')
+    ).toMatchInlineSnapshot(`
+      "// export default
+      class Foo {}
+      const script = Foo"
+    `)
+  })
+
+  test('export default class w/ comments 2', async () => {
+    expect(
+      rewriteDefault(
+        `export default {}\n` + `// export default class Foo {}`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+      "const script = {}
+      // export default class Foo {}"
+    `)
+  })
+
+  test('export default class w/ comments 3', async () => {
+    expect(
+      rewriteDefault(
+        `/*\nexport default class Foo {}*/\n` + `export default class Bar {}`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+      "/*
+      export default class Foo {}*/
+      class Bar {}
+      const script = Bar"
+    `)
+  })
+
+  test('@Component\nexport default class', async () => {
+    expect(rewriteDefault(`@Component\nexport default class Foo {}`, 'script'))
+      .toMatchInlineSnapshot(`
+      "@Component
+      class Foo {}
+      const script = Foo"
+    `)
+  })
+
+  test('@Component\nexport default class w/ comments', async () => {
+    expect(
+      rewriteDefault(`// export default\n@Component\nexport default class Foo {}`, 'script')
+    ).toMatchInlineSnapshot(`
+      "// export default
+      @Component
+      class Foo {}
+      const script = Foo"
+    `)
+  })
+
+  test('@Component\nexport default class w/ comments 2', async () => {
+    expect(
+      rewriteDefault(
+        `export default {}\n` + `// @Component\n// export default class Foo {}`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+      "const script = {}
+      // @Component
+      // export default class Foo {}"
+    `)
+  })
+
+  test('@Component\nexport default class w/ comments 3', async () => {
+    expect(
+      rewriteDefault(
+        `/*\n@Component\nexport default class Foo {}*/\n` + `export default class Bar {}`,
+        'script'
+      )
+    ).toMatchInlineSnapshot(`
+      "/*
+      @Component
+      export default class Foo {}*/
+      class Bar {}
+      const script = Bar"
+    `)
+  })
+})