GraphQL types being defined as unknown in Typescript when compiled by Relay

I am new to using Typescript and finding there is a mismatch in how the types are being handled from the GraphQL schema and types generated via Relay.

Here is an example:

# in schema.graphql
"""
columns and relationships of "businesses"
"""
type businesses implements Node {
  businessId: bigint!
  name: String!
}

// in __generated__/Business_business.graphql
export type Business_business = {
    readonly name: string;
    readonly businessId: unknown;
    readonly " $refType": "Business_business";
};
export type Business_business$data = Business_business;
export type Business_business$key = {
    readonly " $data"?: Business_business$data;
    readonly " $fragmentRefs": FragmentRefs<"Business_business">;
};

const BusinessFragment = graphql`
  fragment Business_business on businesses {
    name
    businessId
  }
`

type Props = {
  fragmentRef: Business_business$key
}

const Business = ({ fragmentRef }: Props) => {
  const business = useFragment(BusinessFragment, fragmentRef)
  return (
    <div>
      <p>my html!</>
      {/* I get the error: Type 'unknown' is not assignable to type 'number' for businessId */}
      <ChildComponent businessId={business.businessId} />
    </div>
  )
}

interface Props {
  businessId: number
}

const ChildComponent = ({ businessId }: Props) => {

  return (
    <p>my business id: {businessId}</p>
  )
}

Is there additional config I need to do to have Relay understand the Hasura types? I have followed the example via the relay docs.

I have the assumption that Relay is not compiling bigint to number.

Update

I have changed the column type in Hasura from bigint to Int and this solved the problem. Is there a way to tell Relay how to match types it is unfamiliar with? In this case cast bigint to number is totally fine.