### Version 2.6.9 ### Reproduction link [https://codesandbox.io/s/pkpkn7ljym](https://codesandbox.io/s/pkpkn7ljym) ### Steps to reproduce Just try to use a `string` value for `VNodeData`'s `style` property. ### What is expected? Vue handle `string` values for `style`, so types should allow the same. ### What is actually happening? Type of `VNodeData`'s `style` don't accept `string` values. --- @flow type declarations has same issue. <!-- generated by vue-issues. DO NOT REMOVE -->