How to use enum from typescript definition file?

I'm programming in nodejs using typescript.

I'm using pdfmake and I installed typescript definition files for this library (@types/pdfmake)

https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/pdfmake/index.d.ts

I'm importing one of the enums from this file

import { PageSize } from "pdfmake/build/pdfmake";

and using it like this PageSize.A4

This compiles, but when I try to access value A4 of this enum, runtime error occurs

TypeError: Cannot read property 'A4' of undefined

Any help would be greatly appreciated

package.json:

{
  "name": "nodejs-pdf-make",
  "version": "1.0.0",
  "description": "",
  "main": "dist/app.js",
  "scripts": {
    "start": "tsc && node --inspect dist/app.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@types/express": "^4.17.1",
    "tslint": "^5.19.0",
    "typescript": "^3.6.2"
  },
  "dependencies": {
    "@types/pdfmake": "^0.1.8",
    "express": "^4.17.1",
    "pdfmake": "^0.1.58"
  }
}

tsconfig.json:

{
  "compilerOptions": {
    "module": "commonjs",
    "esModuleInterop": true,
    "target": "es6",
    "moduleResolution": "node",
    "sourceMap": true,
    "outDir": "dist"
  },
  "lib": ["es2015"]
}```

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