diff --git a/packages/plugin-legacy/index.js b/packages/plugin-legacy/index.js
index bfa6ee491bcbf6..2267cd9cf82b42 100644
--- a/packages/plugin-legacy/index.js
+++ b/packages/plugin-legacy/index.js
@@ -596,7 +596,7 @@ async function buildPolyfillChunk(
   bundle[polyfillChunk.name] = polyfillChunk
 }
 
-const polyfillId = 'vite/legacy-polyfills'
+const polyfillId = '\0vite/legacy-polyfills'
 
 /**
  * @param {Set<string>} imports
diff --git a/packages/vite/src/node/build.ts b/packages/vite/src/node/build.ts
index 47cfd062a7c0bd..3896392e58bdfb 100644
--- a/packages/vite/src/node/build.ts
+++ b/packages/vite/src/node/build.ts
@@ -269,7 +269,7 @@ export function resolveBuildOptions(root: string, raw?: BuildOptions): ResolvedB
     }
   }
 
-  const resolve = (p: string) => path.resolve(root, p)
+  const resolve = (p: string) => p.startsWith('\0') ? p : path.resolve(root, p)
 
   resolved.outDir = resolve(resolved.outDir)