diff --git a/playground/assets-sanitize/__tests__/assets-sanitize.spec.ts b/playground/assets-sanitize/__tests__/assets-sanitize.spec.ts
index e1d60ca90f0368..174cd2188fb3c9 100644
--- a/playground/assets-sanitize/__tests__/assets-sanitize.spec.ts
+++ b/playground/assets-sanitize/__tests__/assets-sanitize.spec.ts
@@ -1,20 +1,27 @@
 import { expect, test } from 'vitest'
-import { getBg, isBuild, listAssets, page } from '~utils'
+import { getBg, isBuild, page, readManifest } from '~utils'
 
 if (!isBuild) {
-  test('importing asset with special char in filename works', async () => {
-    expect(await getBg('.circle-bg')).toContain('+circle.svg')
-    expect(await page.textContent('.circle-bg')).toMatch('+circle.svg')
+  test('importing asset with special char in filename works in dev', async () => {
+    expect(await getBg('.plus-circle')).toContain('+circle.svg')
+    expect(await page.textContent('.plus-circle')).toMatch('+circle.svg')
+    expect(await getBg('.underscore-circle')).toContain('_circle.svg')
+    expect(await page.textContent('.underscore-circle')).toMatch('_circle.svg')
   })
 } else {
-  const expected_asset_name_RE = /_circle\.[\w]+\.svg/
-  test('importing asset with special char in filename works', async () => {
-    expect(await getBg('.circle-bg')).toMatch(expected_asset_name_RE)
-    expect(await page.textContent('.circle-bg')).toMatch(expected_asset_name_RE)
-  })
-  test('asset with special char in filename gets sanitized', async () => {
-    const svgs = listAssets().filter((a) => a.endsWith('.svg'))
-    expect(svgs[0]).toMatch(expected_asset_name_RE)
-    expect(svgs.length).toBe(1)
+  test('importing asset with special char in filename works in build', async () => {
+    const manifest = readManifest()
+    const plusCircleAsset = manifest['+circle.svg'].file
+    const underscoreCircleAsset = manifest['_circle.svg'].file
+    expect(await getBg('.plus-circle')).toMatch(plusCircleAsset)
+    expect(await page.textContent('.plus-circle')).toMatch(plusCircleAsset)
+    expect(await getBg('.underscore-circle')).toMatch(underscoreCircleAsset)
+    expect(await page.textContent('.underscore-circle')).toMatch(
+      underscoreCircleAsset
+    )
+    expect(plusCircleAsset).toMatch('/_circle')
+    expect(underscoreCircleAsset).toMatch('/_circle')
+    expect(plusCircleAsset).not.toBe(underscoreCircleAsset)
+    expect(Object.keys(manifest).length).toBe(3) // 2 svg, 1 index.js
   })
 }
diff --git a/playground/assets-sanitize/_circle.svg b/playground/assets-sanitize/_circle.svg
new file mode 100644
index 00000000000000..f8e310c6148d42
--- /dev/null
+++ b/playground/assets-sanitize/_circle.svg
@@ -0,0 +1,3 @@
+<svg viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <circle cx="12" cy="12" r="10" fill="red"></circle>
+</svg>
diff --git a/playground/assets-sanitize/index.html b/playground/assets-sanitize/index.html
index b9e67642d0023f..e4b4913ca7142c 100644
--- a/playground/assets-sanitize/index.html
+++ b/playground/assets-sanitize/index.html
@@ -1,6 +1,11 @@
 <script type="module" src="./index.js"></script>
-<h1>test element below should show a circle and it's url</h1>
-<div
-  class="circle-bg"
-  style="background-repeat: no-repeat; padding-left: 2rem"
-></div>
+<style>
+  .test-el {
+    background-repeat: no-repeat;
+    padding-left: 2rem;
+    margin-bottom: 1rem;
+  }
+</style>
+<h1>test elements below should show circles and their url</h1>
+<div class="test-el plus-circle"></div>
+<div class="test-el underscore-circle"></div>
diff --git a/playground/assets-sanitize/index.js b/playground/assets-sanitize/index.js
index a9c61f2aadd285..bac3b3b83e6b1d 100644
--- a/playground/assets-sanitize/index.js
+++ b/playground/assets-sanitize/index.js
@@ -1,4 +1,9 @@
-import svg from './+circle.svg'
-const el = document.body.querySelector('.circle-bg')
-el.style.backgroundImage = `url(${svg})`
-el.textContent = svg
+import plusCircle from './+circle.svg'
+import underscoreCircle from './_circle.svg'
+function setData(classname, file) {
+  const el = document.body.querySelector(classname)
+  el.style.backgroundImage = `url(${file})`
+  el.textContent = file
+}
+setData('.plus-circle', plusCircle)
+setData('.underscore-circle', underscoreCircle)