gatsby-transformer-remark optional field in query

[radiKal07]

I use this query in my page to get data from my markdown file:

export const pageQuery = graphql`
  query BlogPostBySlug($slug: String!) {
    site {
      siteMetadata {
        title
        author
      }
    }
    markdownRemark(fields: { slug: { eq: $slug } }) {
      id
      html
      frontmatter {
        title
        date(formatString: "MMMM DD, YYYY")
        name
      }
    }
  }
`

You can see I query title, date and name. I want name to be optional.
If my markdown file does not contain

...
name: whatever
...

Then gatsby fails with error:

error There was an error in your GraphQL query:

Cannot query field "name" on type "MarkdownRemarkFrontmatter".

How can I make this optional? So if it's missing just don't fetch it, populate the data with null value or whatever.