prisma-binding: Duplicate export for `Prisma` Flow generation

Flow generation is super awesome. I just tried it but got an error: Duplicate export for Prisma

projects:
  api:
    schemaPath: "server/api/model.graphql"
    extensions:
      endpoints:
        default: "http://localhost:4000"
  database:
    schemaPath: "database/schema.graphql"
    extensions:
      prisma: database/prisma.yml
      codegen:
        - generator: prisma-binding
          language: flow
          output:
            binding: database/types.js

datamodel: model.graphql

endpoint: ${env:PRISMA_ENDPOINT}

secret: ${env:PRISMA_SECRET}

hooks:
  post-deploy:
    - graphql get-schema --project database
    - graphql codegen

Why it generates both export interface Prisma { and export const Prisma: BindingConstructor<Prisma> = makePrismaBindingClass({typeDefs})? What am I doing wrong?