diff --git a/test/e2e/app-dir/experimental-lightningcss-features/app/custom-media/page.module.css b/test/e2e/app-dir/experimental-lightningcss-features/app/custom-media/page.module.css
new file mode 100644
index 00000000..743b745f
--- /dev/null
+++ b/test/e2e/app-dir/experimental-lightningcss-features/app/custom-media/page.module.css
@@ -0,0 +1,11 @@
+@custom-media --narrow (max-width: 960px);
+
+.box {
+  color: blue;
+}
+
+@media (--narrow) {
+  .box {
+    color: red;
+  }
+}
diff --git a/test/e2e/app-dir/experimental-lightningcss-features/app/custom-media/page.tsx b/test/e2e/app-dir/experimental-lightningcss-features/app/custom-media/page.tsx
new file mode 100644
index 00000000..f4949f6d
--- /dev/null
+++ b/test/e2e/app-dir/experimental-lightningcss-features/app/custom-media/page.tsx
@@ -0,0 +1,5 @@
+import styles from './page.module.css'
+
+export default function Page() {
+  return <div className={styles.box}>Custom media</div>
+}
diff --git a/test/e2e/app-dir/experimental-lightningcss-features/experimental-lightningcss-features.test.ts b/test/e2e/app-dir/experimental-lightningcss-features/experimental-lightningcss-features.test.ts
index ec5ec389..8173b8b6 100644
--- a/test/e2e/app-dir/experimental-lightningcss-features/experimental-lightningcss-features.test.ts
+++ b/test/e2e/app-dir/experimental-lightningcss-features/experimental-lightningcss-features.test.ts
@@ -23,7 +23,7 @@ describe('experimental-lightningcss-features', () => {
   describe('include', () => {
     const { next } = nextTestSetup({
       files: __dirname,
-      dependencies: { lightningcss: '^1.23.0' },
+      dependencies: { lightningcss: '1.33.0' },
       // Chrome 123 supports light-dark() natively — using it here proves that
       // the `include` flag forces transpilation regardless of browser support.
       packageJson: {
@@ -52,10 +52,38 @@ describe('experimental-lightningcss-features', () => {
     })
   })
 
+  describe('custom-media-queries', () => {
+    const { next } = nextTestSetup({
+      files: __dirname,
+      dependencies: { lightningcss: '1.33.0' },
+      packageJson: {
+        browserslist: ['chrome 123'],
+      },
+      nextConfig: {
+        experimental: {
+          useLightningcss: true,
+          lightningCssFeatures: {
+            include: ['custom-media-queries'],
+          },
+        },
+      },
+    })
+
+    it('should substitute @custom-media when custom-media-queries is included', async () => {
+      const html = await next.render('/custom-media')
+      expect(html).toContain('Custom media')
+
+      const css = await collectPageCss(next, '/custom-media')
+      expect(css).not.toContain('@custom-media')
+      expect(css).not.toContain('--narrow')
+      expect(css).toMatch(/max-width:\s*960px|width\s*<=\s*960px/)
+    })
+  })
+
   describe('exclude', () => {
     const { next } = nextTestSetup({
       files: __dirname,
-      dependencies: { lightningcss: '^1.23.0' },
+      dependencies: { lightningcss: '1.33.0' },
       // Chrome 100 does NOT support light-dark() natively, so lightningcss would
       // normally transpile it. Using `exclude: ['light-dark']` should prevent that.
       packageJson: {