Using instanceof SyntaxError does not work with TypeScript

[cmfcmf]

The following code produces an error in TypeScript:

import peggy from "peggy";

const myParser = peggy.generate(`
  Integer "integer"
    = [0-9]+
`);

try {
  myParser.parse("invalid input");
} catch (err) {
  // ERROR: The right-hand side of an 'instanceof' expression must be of type 'any' or of a type assignable to the 'Function' interface type.ts(2359)
  if (err instanceof myParser.SyntaxError) {
    console.log("It is a SyntaxError");
  }
}

(https://codesandbox.io/s/xenodochial-liskov-kmcyk?file=/src/index.ts)

The code reaches the console.log statement, i.e. the JS runs correctly. However, Typescript complains that I cannot use myParser.SyntaxError on the right hand side of the instanceof check. I tried to investigate this, but couldn't figure out why it happens. Something must be wrong with the type definitions (tested on TypeScript 4.4.4).