Global type definition problem

[mb-tousif]

If I declare any custom type in express, typescript project in some where in ./src it does not work. like
in index.d.ts

import { JwtPayload } from 'jsonwebtoken';

declare global {
  namespace Express {
    interface Request {
      user: JwtPayload | null;
    }
  }
}

But When I on top of my middleware file like

import { JwtPayload } from 'jsonwebtoken';

declare global {
  namespace Express {
    interface Request {
      user: JwtPayload | null;
    }
  }
}

const Auth = ()=>{

// SOME Fun

}
export default Auth.

it works.

Please let me know is it ts-node problem or not? and how can I get better solution.