Loading pdfs from a remote server via a stream

I'm trying to load a single PDF from a remote server. Here is my approach:
(I can confirm that if I just pipe the request into a write stream it saves the PDF fine)

var request = require('request');
var pdfParser = require('pdf2json');
var pdfUrl = 'somepdf.pdf'

var pdfPipe = request({url: pdfUrl, encoding:null}).pipe(pdfParser);

pdfPipe.on("pdfParser_dataError", err => console.error(err) );
pdfPipe.on("pdfParser_dataReady", pdf => {
    //let pdf = pdfParser.getMergedTextBlocksIfNeeded();
    console.log(pdfParser.getAllFieldsTypes());
});

However, I'm getting an error:

stream.js:45
  dest.on('drain', ondrain);
       ^

TypeError: dest.on is not a function
    at Request.Stream.pipe (stream.js:45:8)
    at Request.pipe (/Users/zaf/development/minerva-bot/node_modules/request/request.js:1395:34)
    at Object.<anonymous> (/Users/zaf/development/minerva-bot/plugins/exam_module/index.js:9:53)
    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

Code constructed from here: http://stackoverflow.com/a/36882510/3779915

Start at plugins/exam_module/index.js:9 and trace the Request.pipe call shown in the stack through stream.js:45 and request/request.js:1395. Reproduce the remote PDF stream case and inspect whether pdfParser is a valid destination; done means the request no longer raises the reported TypeError and the parser emits its documented data event.