### Version 3.4.1 ### Reproduction link [https://jsfiddle.net/cympopcorn/0e8psq2x/4/](https://jsfiddle.net/cympopcorn/0e8psq2x/4/) ### Steps to reproduce 1. Click the 'a' link 1. Click 'pushQuery' button 1. Check the 'Console' ### What is expected? "update", { text: 2, value: 1 } ### What is actually happening? "update", "[object Object]" <!-- generated by vue-issues. DO NOT REMOVE -->