diff --git a/packages/vitest/src/runtime/setup.ts b/packages/vitest/src/runtime/setup.ts
index c6d7b679f4e1..3d6185b0b00f 100644
--- a/packages/vitest/src/runtime/setup.ts
+++ b/packages/vitest/src/runtime/setup.ts
@@ -1,3 +1,5 @@
+/* eslint-disable n/no-deprecated-api */
+
 import { installSourcemapsSupport } from 'vite-node/source-map'
 import { environments } from '../integrations/env'
 import type { Environment, ResolvedConfig } from '../types'
@@ -23,6 +25,11 @@ export async function setupGlobalEnv(config: ResolvedConfig) {
   if (globalSetup)
     return
 
+  // always mock "required" `css` files, because we cannot process them
+  require.extensions['.css'] = () => ({})
+  require.extensions['.scss'] = () => ({})
+  require.extensions['.sass'] = () => ({})
+
   globalSetup = true
 
   if (isNode) {
diff --git a/test/core/src/file-css.css b/test/core/src/file-css.css
new file mode 100644
index 000000000000..c6dd2c88fabe
--- /dev/null
+++ b/test/core/src/file-css.css
@@ -0,0 +1,3 @@
+.red {
+  color: red;
+}
diff --git a/test/core/src/file-sass.sass b/test/core/src/file-sass.sass
new file mode 100644
index 000000000000..dcb2babacb1c
--- /dev/null
+++ b/test/core/src/file-sass.sass
@@ -0,0 +1,2 @@
+.red
+  color: red;
diff --git a/test/core/src/file-scss.scss b/test/core/src/file-scss.scss
new file mode 100644
index 000000000000..c6dd2c88fabe
--- /dev/null
+++ b/test/core/src/file-scss.scss
@@ -0,0 +1,3 @@
+.red {
+  color: red;
+}
diff --git a/test/core/test/require.test.ts b/test/core/test/require.test.ts
new file mode 100644
index 000000000000..a26e1f59e177
--- /dev/null
+++ b/test/core/test/require.test.ts
@@ -0,0 +1,15 @@
+import { describe, expect, it } from 'vitest'
+
+const _require = require
+
+describe('using "require" to import a module', () => {
+  it('importing css files works, but doesn\'t process them', () => {
+    const css = _require('./../src/file-css.css')
+    const sass = _require('./../src/file-sass.sass')
+    const scss = _require('./../src/file-scss.scss')
+
+    expect(css).toEqual({})
+    expect(sass).toEqual({})
+    expect(scss).toEqual({})
+  })
+})