react-hook-form types

I'm using react-hook-form with typescript and I changed from using the

useForm

useForm

to the

useFormContext

useFormContext

and Typescript brought to my attention that the types of the errors are not the same. Using

useForm

useForm

errors.firstName.message

errors.firstName.message

is of type string as I would expect, but with the context version, the type is

string | FieldError | Merge<FieldError, FieldErrorsImpl<any>> | undefined

string | FieldError | Merge<FieldError, FieldErrorsImpl<any>> | undefined

. Why are these types different and how do I just get the message while using the context version?