diff --git a/packages/runtime-core/src/warning.ts b/packages/runtime-core/src/warning.ts
index 16928387dfb..c3b2ebbd02d 100644
--- a/packages/runtime-core/src/warning.ts
+++ b/packages/runtime-core/src/warning.ts
@@ -45,7 +45,7 @@ export function warn(msg: string, ...args: any[]) {
       instance,
       ErrorCodes.APP_WARN_HANDLER,
       [
-        msg + args.join(''),
+        msg + args.map(a => a.toString?.() ?? JSON.stringify(a)).join(''),
         instance && instance.proxy,
         trace
           .map(