diff --git a/packages/vite/src/node/server/index.ts b/packages/vite/src/node/server/index.ts
index 34a0b5b6a080c4..772b163a745eb7 100644
--- a/packages/vite/src/node/server/index.ts
+++ b/packages/vite/src/node/server/index.ts
@@ -1022,7 +1022,7 @@ export const serverConfigDefaults = Object.freeze({
   host: 'localhost',
   https: undefined,
   open: false,
-  proxy: {},
+  proxy: undefined,
   cors: true,
   headers: {},
   // hmr