Error: Protocol "http:" not supported. Expected "https:"

I am trying to mock all requests to a specific domain, excluding a single request based on body vars.
Using the following nock code:

nock('https://www.example.com', { allowUnmocked: true })
  .persist()
  .post('/api/method', (body) => {
    // here is a check for the presence of a certain body variable
    // returning false for example purposes
    return false;
  })
  .reply(200, {
    success: true,
  });

The result error is:
Error: Protocol "http:" not supported. Expected "https:"

I have tried it both with axios and request to ensure that it’s not an axios issue.

Stack trace while using axios:

at new ClientRequest (_http_client.js:54:11)
at end (node_modules/nock/lib/request_overrider.js:257:24)
at OverriddenClientRequest.RequestOverrider.req.end (node_modules/nock/lib/request_overrider.js:165:7)
at Writable.RedirectableRequest.end (node_modules/follow-redirects/index.js:203:23)
at dispatchHttpRequest (node_modules/axios/lib/adapters/http.js:228:11)
at httpAdapter (node_modules/axios/lib/adapters/http.js:18:10)
at dispatchRequest (node_modules/axios/lib/core/dispatchRequest.js:52:10)
at process._tickDomainCallback (internal/process/next_tick.js:135:7)

Stack trace while using request:

at new ClientRequest (_http_client.js:54:11)
at end (node_modules/nock/lib/request_overrider.js:257:24)
at OverriddenClientRequest.RequestOverrider.req.end (node_modules/nock/lib/request_overrider.js:165:7)
at Request.end (node_modules/request/request.js:1515:14)
at end (node_modules/request/request.js:548:16)
at Immediate.<anonymous> (node_modules/request/request.js:575:7)

nock: 9.0.15 axios: 0.16.2 request: 2.82.0 node: 6.11.3