-O in JSON format throws error

[Austneal]

On Windows, using this command

pug -O '{"foo": "bar"}' index.pug

with this file

h1 Main Page
p This is the main page.
p= foo

throws the following error:

('{foo:)
 ^^^^^^^

SyntaxError: Unexpected token ILLEGAL
    at parseObj (c:\node\node_modules\pug-cli\index.js:101:29)
    at Object.<anonymous> (c:\node\node_modules\pug-cli\index.js:81:13)
    at Module._compile (module.js:434:26)
    at Object.Module._extensions..js (module.js:452:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Function.Module.runMain (module.js:475:10)
    at startup (node.js:117:18)
    at node.js:951:3

Using -O with the "javascript format" works correctly.

EDIT: It seems to be an issue with the quotes. pug -O "{'foo': 'bar'}" index.pug This works correctly.