diff --git a/lib/error.js b/lib/error.js
index c68b028083..66fd720d36 100644
--- a/lib/error.js
+++ b/lib/error.js
@@ -45,6 +45,7 @@ Util.inherits(exports.HttpError, Error);
 }).call(exports.HttpError.prototype)
 
 var statusCodes = {
+  304: 'Not Modified', // See PR #673 (https://github.com/octokit/node-github/pull/673)
   400: 'Bad Request',
   401: 'Unauthorized',
   402: 'Payment Required',
diff --git a/lib/index.js b/lib/index.js
index 74af1ca1c2..fdd98bb098 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -738,13 +738,13 @@ var Client = module.exports = function (config) {
           callCallback(err)
         })
         res.on('end', function () {
-          if (res.statusCode >= 301 && res.statusCode <= 307) {
+          if (res.statusCode !== 304 && res.statusCode >= 301 && res.statusCode <= 307) {
             options.path = Url.parse(res.headers.location, true).path
             httpSendRequest()
             return
           }
 
-          if (res.statusCode >= 400 || res.statusCode < 10) {
+          if (res.statusCode === 304 || res.statusCode >= 400 || res.statusCode < 10) {
             callCallback(new error.HttpError(data, res.statusCode, res.headers))
           } else {
             res.data = data
diff --git a/test/integration/conditional-request-test.js b/test/integration/conditional-request-test.js
new file mode 100644
index 0000000000..045729eba5
--- /dev/null
+++ b/test/integration/conditional-request-test.js
@@ -0,0 +1,42 @@
+const chai = require('chai')
+const nock = require('nock')
+
+const GitHub = require('../../')
+
+const mocha = require('mocha')
+const describe = mocha.describe
+const it = mocha.it
+chai.should()
+
+describe('request 304s', () => {
+  it('304 etag', () => {
+    nock('https://request-errors-test.com')
+      .get('/orgs/myorg')
+      .reply(304, '')
+
+    const github = new GitHub({
+      host: 'request-errors-test.com'
+    })
+
+    return github.orgs.get({org: 'myorg', headers: {'If-None-Match': 'etag'}})
+
+    .catch(exception => {
+      exception.code.should.equal(304)
+    })
+  })
+  it('304 last-modified', () => {
+    nock('https://request-errors-test.com')
+      .get('/orgs/myorg')
+      .reply(304, '')
+
+    const github = new GitHub({
+      host: 'request-errors-test.com'
+    })
+
+    return github.orgs.get({org: 'myorg', headers: {'If-Modified-Since': 'Sun Dec 24 2017 22:00:00 GMT-0600 (CST)'}})
+
+    .catch(exception => {
+      exception.code.should.equal(304)
+    })
+  })
+})