diff --git a/src/vite/manifest.ts b/src/vite/manifest.ts
index 87a17faf..d1ce9dc2 100644
--- a/src/vite/manifest.ts
+++ b/src/vite/manifest.ts
@@ -95,8 +95,8 @@ export async function generateBuildManifest (ctx: ViteBuildContext) {
     'var appConfig = window && window.__NUXT__ && window.__NUXT__.config.app || {}',
     'var publicBase = appConfig.cdnURL || appConfig.baseURL || "/"',
     'function joinURL (a, b) { return a[a.length -1] !== "/" ? a + "/" + b : a + b }',
-    'globalThis.__publicAssetsURL = function(id) { return joinURL(publicBase, id) }',
-    'globalThis.__buildAssetsURL = function(id) { return joinURL(publicBase, joinURL(appConfig.buildAssetsDir, id)) }',
+    'globalThis.__publicAssetsURL = function(id) { return joinURL(publicBase, id || "") }',
+    'globalThis.__buildAssetsURL = function(id) { return joinURL(publicBase, joinURL(appConfig.buildAssetsDir, id || "")) }',
     `var imports = ${JSON.stringify([...clientImports])};`,
     'imports.reduce(function(p, id){return p.then(function(){return System.import(__buildAssetsURL(id).slice(1))})}, Promise.resolve())'
   ].join('\n')
diff --git a/test/bridge.test.ts b/test/bridge.test.ts
index 175d3919..9dca3a87 100644
--- a/test/bridge.test.ts
+++ b/test/bridge.test.ts
@@ -82,7 +82,8 @@ describe('dynamic paths', () => {
     await expectNoClientErrors('/assets')
   })
 
-  it('adds relative paths to CSS', async () => {
+  // Vite legacy build does not emit CSS files
+  it.skipIf(!process.env.TEST_WITH_WEBPACK)('adds relative paths to CSS', async () => {
     const html = await $fetch('/assets')
     const urls = Array.from(html.matchAll(/(href|src)="(.*?)"/g)).map(m => m[2])
     const cssURL = urls.find(u => /_nuxt\/assets.*\.css$/.test(u))