diff --git a/modules/rubiconAnalyticsAdapter.js b/modules/rubiconAnalyticsAdapter.js
index 939afc42f6d..9bb8a924b98 100644
--- a/modules/rubiconAnalyticsAdapter.js
+++ b/modules/rubiconAnalyticsAdapter.js
@@ -37,11 +37,14 @@ const cache = {
   timeouts: {},
 };
 
-let referrerHostname;
-
-function getHostNameFromReferer(referer) {
-  referrerHostname = urlLib.parse(referer).hostname;
-  return referrerHostname;
+export function getHostNameFromReferer(referer) {
+  try {
+    rubiconAdapter.referrerHostname = urlLib.parse(referer, {noDecodeWholeURL: true}).hostname;
+  } catch (e) {
+    utils.logError('Rubicon Analytics: Unable to parse hostname from supplied url: ', referer, e);
+    rubiconAdapter.referrerHostname = '';
+  }
+  return rubiconAdapter.referrerHostname
 };
 
 function stringProperties(obj) {
@@ -124,7 +127,7 @@ function sendMessage(auctionId, bidWonId) {
     integration: config.getConfig('rubicon.int_type') || DEFAULT_INTEGRATION,
     version: '$prebid.version$',
     referrerUri: referrer,
-    referrerHostname: referrerHostname || getHostNameFromReferer(referrer)
+    referrerHostname: rubiconAdapter.referrerHostname || getHostNameFromReferer(referrer)
   };
   const wrapperName = config.getConfig('rubicon.wrapperName');
   if (wrapperName) {
@@ -269,6 +272,7 @@ function setRubiconAliases(aliasRegistry) {
 
 let baseAdapter = adapter({analyticsType: 'endpoint'});
 let rubiconAdapter = Object.assign({}, baseAdapter, {
+  referrerHostname: '',
   enableAnalytics(config = {}) {
     let error = false;
     samplingFactor = 1;
diff --git a/test/spec/modules/rubiconAnalyticsAdapter_spec.js b/test/spec/modules/rubiconAnalyticsAdapter_spec.js
index 2ad828ef3e0..1e71a43999d 100644
--- a/test/spec/modules/rubiconAnalyticsAdapter_spec.js
+++ b/test/spec/modules/rubiconAnalyticsAdapter_spec.js
@@ -1,4 +1,8 @@
-import rubiconAnalyticsAdapter, { SEND_TIMEOUT, parseBidResponse } from 'modules/rubiconAnalyticsAdapter.js';
+import rubiconAnalyticsAdapter, {
+  SEND_TIMEOUT,
+  parseBidResponse,
+  getHostNameFromReferer,
+} from 'modules/rubiconAnalyticsAdapter.js';
 import CONSTANTS from 'src/constants.json';
 import { config } from 'src/config.js';
 import { server } from 'test/mocks/xhr.js';
@@ -22,9 +26,8 @@ function validate(message) {
 }
 
 // using es6 "import * as events from 'src/events.js'" causes the events.getEvents stub not to work...
-let events = require('src/events');
-let ajax = require('src/ajax');
-let utils = require('src/utils');
+let events = require('src/events.js');
+let utils = require('src/utils.js');
 
 const {
   EVENTS: {
@@ -477,7 +480,6 @@ function performStandardAuction() {
 
 describe('rubicon analytics adapter', function () {
   let sandbox;
-  let oldScreen;
   let clock;
 
   beforeEach(function () {
@@ -487,6 +489,8 @@ describe('rubicon analytics adapter', function () {
 
     clock = sandbox.useFakeTimers(1519767013781);
 
+    rubiconAnalyticsAdapter.referrerHostname = '';
+
     config.setConfig({
       s2sConfig: {
         timeout: 1000,
@@ -841,4 +845,19 @@ describe('rubicon analytics adapter', function () {
       rubiconAnalyticsAdapter.disableAnalytics();
     });
   });
+
+  it('getHostNameFromReferer correctly grabs hostname from an input URL', function () {
+    let inputUrl = 'https://www.prebid.org/some/path?pbjs_debug=true';
+    expect(getHostNameFromReferer(inputUrl)).to.equal('www.prebid.org');
+    inputUrl = 'https://www.prebid.com/some/path?pbjs_debug=true';
+    expect(getHostNameFromReferer(inputUrl)).to.equal('www.prebid.com');
+    inputUrl = 'https://prebid.org/some/path?pbjs_debug=true';
+    expect(getHostNameFromReferer(inputUrl)).to.equal('prebid.org');
+    inputUrl = 'http://xn--p8j9a0d9c9a.xn--q9jyb4c/';
+    expect(getHostNameFromReferer(inputUrl)).to.equal('xn--p8j9a0d9c9a.xn--q9jyb4c');
+
+    // not non-UTF char's in query / path which break if noDecodeWholeURL not set
+    inputUrl = 'https://prebid.org/search_results/%95x%8Em%92%CA/?category=000';
+    expect(getHostNameFromReferer(inputUrl)).to.equal('prebid.org');
+  });
 });