diff --git a/HISTORY.md b/HISTORY.md
index 5b4983d4..6b573a40 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,3 +1,7 @@
+# 4.1.7 / 2021-03-17
+
+- Fix Potential DOM-based XSS via prototype pollution
+
 # 4.1.6 / 2020-11-24
 
 - Update `trim` package to address ReDoS vulnerability
diff --git a/lib/analytics.ts b/lib/analytics.ts
index 73080872..5427ea60 100644
--- a/lib/analytics.ts
+++ b/lib/analytics.ts
@@ -6,13 +6,14 @@ import {
   SegmentAnalytics,
   SegmentOpts,
   SegmentIntegration,
-  PageDefaults, Message
+  PageDefaults
 } from './types';
 
 import { pageDefaults } from './pageDefaults';
 
 import cloneDeep from 'lodash.clonedeep'
 import pick from 'lodash.pick'
+import url from 'component-url'
 
 var _analytics = global.analytics;
 
@@ -37,7 +38,6 @@ var extend = require('extend');
 var cookie = require('./cookie');
 var metrics = require('./metrics');
 var debug = require('debug');
-var defaults = require('@ndhoule/defaults');
 var group = require('./group');
 var is = require('is');
 var isMeta = require('@segment/is-meta');
@@ -46,7 +46,6 @@ var nextTick = require('next-tick');
 var normalize = require('./normalize');
 var on = require('component-event').bind;
 var prevent = require('@segment/prevent-default');
-var querystring = require('component-querystring');
 var store = require('./store');
 var user = require('./user');
 var type = require('component-type');
@@ -69,7 +68,6 @@ function Analytics() {
   this.log = debug('analytics.js');
   bindAll(this);
 
-
   const self = this;
   this.on('initialize', function(_, options) {
     if (options.initialPageview) self.page();
@@ -960,9 +958,22 @@ Analytics.prototype.reset = function() {
  * @api private
  */
 
+interface QueryStringParams {
+  [key: string]: string | null;
+}
+
 Analytics.prototype._parseQuery = function(query: string): SegmentAnalytics {
   // Parse querystring to an object
-  var q = querystring.parse(query);
+  const parsed = url.parse(query);
+
+  const q = parsed.query
+    .split('&')
+    .reduce((acc: QueryStringParams, str: string) => {
+      const [k, v] = str.split('=');
+      acc[k] = decodeURI(v).replace('+', ' ');
+      return acc;
+    }, {});
+
   // Create traits and properties objects, populate from querysting params
   var traits = pickPrefix('ajs_trait_', q);
   var props = pickPrefix('ajs_prop_', q);
diff --git a/package.json b/package.json
index 1087f28f..065a3e3e 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,6 @@
     "bind-all": "^1.0.0",
     "component-emitter": "^1.2.1",
     "component-event": "^0.1.4",
-    "component-querystring": "^2.0.0",
     "component-type": "^1.2.1",
     "component-url": "^0.2.1",
     "debug": "^2.6.9",
diff --git a/yarn.lock b/yarn.lock
index 60c9da5e..5e50af65 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2526,21 +2526,10 @@ component-props@*:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/component-props/-/component-props-1.1.1.tgz#f9b7df9b9927b6e6d97c9bd272aa867670f34944"
 
-component-querystring@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/component-querystring/-/component-querystring-2.0.0.tgz#84a95d18e471c8491b043df240f0d18d4db527ec"
-  dependencies:
-    component-type "1.1.0"
-    trim "0.0.1"
-
 component-type@1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/component-type/-/component-type-1.0.0.tgz#1ed8812e32dd65099d433570757f111ea3d3d871"
 
-component-type@1.1.0:
-  version "1.1.0"
-  resolved "https://registry.yarnpkg.com/component-type/-/component-type-1.1.0.tgz#95b666aad53e5c8d1f2be135c45b5d499197c0c5"
-
 component-type@^1.2.0, component-type@^1.2.1:
   version "1.2.1"
   resolved "https://registry.yarnpkg.com/component-type/-/component-type-1.2.1.tgz#8a47901700238e4fc32269771230226f24b415a9"