Yargs throwing an error when trying to access argv members

Question

I have

import * as yargs from 'yargs'

let args = yargs
    .option('address', {
        alias: 'a',
        description: "address",
        demand: true,
        type: "string"
    })
    .option('network', {
        alias: 'n',
        description: "network",
        demand: true,
        type: "string"
    }).argv

console.log(args)

After running the script with yarn ts-node script.ts --address 0x3cb7d3842e8cee6a0ebd09f1fe884f6861e1b29c --network flare I get

{
  _: [],
  address: '0x3cb7d3842e8cee6a0ebd09f1fe884f6861e1b29c',
  a: '0x3cb7d3842e8cee6a0ebd09f1fe884f6861e1b29c',
  network: 'flare',
  n: 'flare',
  '$0': 'node_modules\\ts-node\\dist\\bin.js'
}

But then when I try to access members e.g. argv.address it throws me a typescript compilation error

TSError: ⨯ Unable to compile TypeScript:
src/toPChainAddress.ts:19:18 - error TS2339: Property 'a' does not exist on type '{ [x: string]: unknown; address: string; network: string; _: (string | number)[]; $0: string; } | Promise<{ [x: string]: unknown; address: string; network: string; _: (string | number)[]; $0: string; }>'.
  Property 'a' does not exist on type 'Promise<{ [x: string]: unknown; address: string; network: string; _: (string | number)[]; $0: string; }>'.

19 console.log(args.a)