Vuetify v文件输入“ onchange”正常工作但未收到事件

Please take a look at my code below. My input works well, but not the v-file-input:

<v-file-input
  accept=".json"
  ref="loadedFile"
  label="Upload file"
  @change="checkJSON"
  ></v-file-input>

<input
    type="file"
    accept=".json"
    @change="checkJSON"
    >



methods: {
  checkJSON: function(e) {
    console.log("JSON checking")
    console.log(JSON.stringify(e))
    console.log(e.target.files)
    return
  }
}

The console shows the file for the input, but here is the message I get for the v-file-input:

[Vue warn]: Error in v-on handler: "TypeError: e.target is undefined"

那是正常的吗?我想使用vuetify组件,它更漂亮。 提前致谢。