diff --git a/src/mount.ts b/src/mount.ts
index f3c383d961..74df2cfa00 100644
--- a/src/mount.ts
+++ b/src/mount.ts
@@ -464,10 +464,6 @@ export function mount(
   // if not, use the return value from app.mount.
   const appRef = vm.$refs[MOUNT_COMPONENT_REF] as ComponentPublicInstance
   const $vm = Reflect.ownKeys(appRef).length ? appRef : vm
-  // we add `hasOwnProperty` so jest can spy on the proxied vm without throwing
-  $vm.hasOwnProperty = (property) => {
-    return Reflect.has($vm, property)
-  }
   console.warn = warnSave
   return createWrapper(app, $vm, setProps)
 }