diff --git a/integrations/marketo-v2/HISTORY.md b/integrations/marketo-v2/HISTORY.md
index 5974476f9..b00d4a0ec 100644
--- a/integrations/marketo-v2/HISTORY.md
+++ b/integrations/marketo-v2/HISTORY.md
@@ -1,3 +1,11 @@
+4.0.0 / 2021-09-09
+=================
+
+  * Deprecate associateLead method
+  * Remove email hash method
+  * Add support for Marketo forms
+  * Add support for marketoFormId and marketoHostUrl settings
+
 3.0.7 / 2018-02-23
 ==================
 
diff --git a/integrations/marketo-v2/lib/index.js b/integrations/marketo-v2/lib/index.js
index 41b196f85..c62201d2b 100644
--- a/integrations/marketo-v2/lib/index.js
+++ b/integrations/marketo-v2/lib/index.js
@@ -4,13 +4,12 @@
  * Module dependencies.
  */
 
-var fmt = require('@segment/fmt');
 var integration = require('@segment/analytics.js-integration');
 var is = require('is');
-var jsonp = require('jsonp');
 var url = require('component-url');
 var when = require('do-when');
 var each = require('@ndhoule/each');
+
 // mapping of Standard Marketo API names: restAPIName: soapAPIName
 var apiNameMapping = {
   annualRevenue: 'AnnualRevenue',
@@ -82,11 +81,29 @@ var apiNameMapping = {
 var Marketo = (module.exports = integration('Marketo V2')
   .assumesPageview()
   .global('Munchkin')
+  .global('MktForms2')
   .option('host', 'https://api.segment.io')
   .option('accountId', '')
   .option('projectId', '')
+  .option('marketoHostUrl', '')
+  .option('marketoFormId', '')
   .option('traits', [])
-  .tag('<script src="//munchkin.marketo.net/munchkin.js">'));
+  .tag('<script src="//munchkin.marketo.net/munchkin.js">')
+  .tag(
+    'forms',
+    '<script src="{{marketoHostUrl}}/js/forms2/js/forms2.min.js">'
+  ));
+
+var disableFormSubmitRedirects = function(form) {
+  if (form) {
+    // *** Do not remove this callback ***
+    // This ensures there are no page refreshes after the form is submitted and handles
+    // the side effects of multiple form submissions in the same page.
+    form.onSuccess(function() {
+      return false;
+    });
+  }
+};
 
 /**
  * Initialize.
@@ -97,11 +114,29 @@ var Marketo = (module.exports = integration('Marketo V2')
  */
 
 Marketo.prototype.initialize = function() {
+  var munchkinId = this.options.accountId;
+  var marketoHostUrl = this.options.marketoHostUrl;
+  var marketoFormId = parseInt(this.options.marketoFormId, 10);
+
+  var identifySettingsAreInvalid =
+    marketoHostUrl === undefined ||
+    marketoHostUrl === '' ||
+    Number.isNaN(marketoFormId) ||
+    marketoFormId <= 0;
+
+  if (identifySettingsAreInvalid) {
+    console.warn(
+      'Invalid settings for identify method. Please review your Marketo V2 destination settings.'
+    );
+    return;
+  }
+
   var self = this;
   this.load(function() {
-    window.Munchkin.init(self.options.accountId, {
+    window.Munchkin.init(munchkinId, {
       asyncOnly: true
     });
+
     // marketo integration actually loads a marketo snippet
     // and the snippet loads the real marketo, this is required
     // because there's a race between `window.mktoMunchkinFunction = sinon.spy()`
@@ -109,6 +144,21 @@ Marketo.prototype.initialize = function() {
     // and deletes the spy.
     when(self.loaded, self.ready);
   });
+
+  this.load('forms', { marketoHostUrl: marketoHostUrl }, function() {
+    var marketoForm = document.createElement('form');
+    marketoForm.setAttribute('id', 'mktoForm_' + marketoFormId);
+    marketoForm.setAttribute('style', 'display:none');
+    document.body.appendChild(marketoForm);
+    window.MktoForms2.loadForm(
+      marketoHostUrl,
+      munchkinId,
+      marketoFormId,
+      function(form) {
+        disableFormSubmitRedirects(form);
+      }
+    );
+  });
 };
 
 /**
@@ -141,6 +191,12 @@ Marketo.prototype.page = function(page) {
   });
 };
 
+Marketo.prototype.setupAndSubmitForm = function(traits, form) {
+  form.addHiddenFields(traits, form);
+  disableFormSubmitRedirects(form);
+  form.submit();
+};
+
 /**
  * Identify.
  *
@@ -154,6 +210,7 @@ Marketo.prototype.identify = function(identify) {
     return;
   }
 
+  var self = this;
   var settings = this.options;
 
   // we _must_ have an email
@@ -216,50 +273,12 @@ Marketo.prototype.identify = function(identify) {
     }
   }, settings.traits);
 
-  // associate the lead on the client-side so that
-  // we can track to the same user
-  this.requestHash(traitsToSendMarketo.Email, function(err, hash) {
-    var marketoFn = window.mktoMunchkinFunction;
-    if (marketoFn) marketoFn('associateLead', traitsToSendMarketo, hash);
-  });
-};
-
-/**
- * Generate the URL to the Segment endpoint that hashes Marketo emails.
- *
- * @api private
- * @param {string} email
- * @return {string}
- */
-
-Marketo.prototype.emailHashUrl = function(email) {
-  var host = this.options.host;
-  var projectId = this.options.projectId;
-  return fmt(
-    '%s/integrations/marketo/v1/%s/%s/hash-v2',
-    host,
-    projectId,
-    email
-  );
-};
-
-/**
- * Marketo requires that users' requests come with a hashed version of their
- * email address. It's a hash that can't be done on the client-side for some
- * reason.
- *
- * Man, it'd have been great if someone had documented this in the first place.
- *
- * See https://github.com/segmentio/marketo-hash-app for more details.
- *
- * TODO: Improve this documentation
- *
- * @api private
- * @param {string} email
- * @param {Function} callback
- */
+  window.MktoForms2.whenReady(function(form) {
+    var marketoFormId = parseInt(settings.marketoFormId, 10);
+    var validFormId = !(Number.isNaN(marketoFormId) || marketoFormId <= 0);
 
-Marketo.prototype.requestHash = function(email, callback) {
-  var url = this.emailHashUrl(email);
-  jsonp(url, callback);
+    if (validFormId && form.getId() === marketoFormId) {
+      self.setupAndSubmitForm(traitsToSendMarketo, form);
+    }
+  });
 };
diff --git a/integrations/marketo-v2/package.json b/integrations/marketo-v2/package.json
index d3327f73e..28d2440e7 100644
--- a/integrations/marketo-v2/package.json
+++ b/integrations/marketo-v2/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@segment/analytics.js-integration-marketo-v2",
   "description": "The Marketo analytics.js integration.",
-  "version": "3.0.8",
+  "version": "4.0.1",
   "keywords": [
     "analytics.js",
     "analytics.js-integration",
diff --git a/integrations/marketo-v2/test/index.test.js b/integrations/marketo-v2/test/index.test.js
index 614adbb25..8a1f7c18f 100644
--- a/integrations/marketo-v2/test/index.test.js
+++ b/integrations/marketo-v2/test/index.test.js
@@ -1,13 +1,11 @@
 'use strict';
 
 var Analytics = require('@segment/analytics.js-core').constructor;
-var assert = require('proclaim');
-var fmt = require('@segment/fmt');
 var integration = require('@segment/analytics.js-integration');
 var sandbox = require('@segment/clear-env');
 var tester = require('@segment/analytics.js-integration-tester');
-var url = require('component-url');
 var when = require('do-when');
+var url = require('component-url');
 var Marketo = require('../lib/');
 
 /**
@@ -18,30 +16,34 @@ var Marketo = require('../lib/');
 describe('Marketo', function() {
   var analytics;
   var marketo;
-  var options = {
-    projectId: 'Pk6s0Q47fC',
-    accountId: '332-UOQ-444',
-    traits: [
-      {
-        key: 'customTrait',
-        value: {
-          segmentTrait: 'customTrait',
-          marketoFieldName: 'Mylittleponyz',
-          marketoFieldType: 'string'
-        }
-      },
-      {
-        key: 'fax',
-        value: {
-          segmentTrait: 'fax',
-          marketoFieldName: 'fax',
-          marketoFieldType: 'number'
-        }
-      }
-    ]
-  };
+  var options;
 
   beforeEach(function() {
+    options = {
+      projectId: 'Pk6s0Q47fC',
+      accountId: 'app-ab28.marketo.com',
+      marketoFormId: '1003',
+      marketoHostUrl: '//app-ab28.marketo.com',
+      traits: [
+        {
+          key: 'customTrait',
+          value: {
+            segmentTrait: 'customTrait',
+            marketoFieldName: 'Mylittleponyz',
+            marketoFieldType: 'string'
+          }
+        },
+        {
+          key: 'fax',
+          value: {
+            segmentTrait: 'fax',
+            marketoFieldName: 'fax',
+            marketoFieldType: 'number'
+          }
+        }
+      ]
+    };
+
     analytics = new Analytics();
     marketo = new Marketo(options);
     analytics.use(Marketo);
@@ -62,10 +64,18 @@ describe('Marketo', function() {
       integration('Marketo V2')
         .assumesPageview()
         .global('Munchkin')
+        .global('MktForms2')
         .option('host', 'https://api.segment.io')
         .option('accountId', '')
         .option('projectId', '')
+        .option('marketoHostUrl', '')
+        .option('marketoFormId', '')
         .option('traits', [])
+        .tag('<script src="//munchkin.marketo.net/munchkin.js">')
+        .tag(
+          'forms',
+          '<script src="{{marketoHostUrl}}/js/forms2/js/forms2.min.js">'
+        )
     );
   });
 
@@ -76,7 +86,7 @@ describe('Marketo', function() {
 
     describe('#initialize', function() {
       it('should call #load', function() {
-        analytics.initialize();
+        analytics.initialize(options);
         analytics.page({}, { Marketo: true });
         analytics.called(marketo.load);
       });
@@ -92,7 +102,7 @@ describe('Marketo', function() {
   describe('after loading', function() {
     beforeEach(function(done) {
       analytics.once('ready', done);
-      analytics.initialize();
+      analytics.initialize(options);
       analytics.page({}, { Marketo: true });
     });
 
@@ -137,27 +147,20 @@ describe('Marketo', function() {
     });
 
     describe('#identify', function() {
-      beforeEach(function() {
-        analytics.user().anonymousId('fc42baa7-6aa4-4500-9ebb-0548762a6ac8');
-        analytics.spy(marketo, 'requestHash');
-        analytics.stub(window, 'mktoMunchkinFunction');
-      });
+      var form;
 
-      it('should call window.mktoMunchkinFunction', function(done) {
-        analytics.identify(
-          'id',
-          { email: 'name@example.com' },
-          { Marketo: true }
-        );
-        analytics.equal(marketo.requestHash.args[0][0], 'name@example.com');
-        when(function() {
-          return window.mktoMunchkinFunction.called;
-        }, done);
-      });
+      beforeEach(function() {
+        // Mock form
+        form = {
+          submit: function() {
+            return true;
+          }
+        };
 
-      it('should not call `.requestHash` without an email', function() {
-        analytics.identify('id', {}, { Marketo: true });
-        analytics.didNotCall(marketo.requestHash);
+        analytics.spy(marketo, 'setupAndSubmitForm');
+        analytics.spy(form, 'submit');
+        analytics.stub(window.MktoForms2, 'loadForm');
+        analytics.stub(window.MktoForms2, 'whenReady');
       });
 
       it('should return out if Marketo is disabled', function() {
@@ -166,18 +169,15 @@ describe('Marketo', function() {
           {},
           { integrations: { Marketo: false } }
         );
-        analytics.didNotCall(marketo.requestHash);
+        analytics.didNotCall(window.MktoForms2.loadForm);
       });
 
-      it('should grab email from id', function(done) {
-        analytics.identify('name@example.com', {}, { Marketo: true });
-        analytics.equal(marketo.requestHash.args[0][0], 'name@example.com');
-        when(function() {
-          return window.mktoMunchkinFunction.called;
-        }, done);
+      it('should return out if no email is passed', function() {
+        analytics.identify('', {}, { integrations: { Marketo: false } });
+        analytics.didNotCall(window.MktoForms2.loadForm);
       });
 
-      it('should call window.mktoMunchkinFunction with special traits', function(done) {
+      it('should submit form with traits', function(done) {
         var traits = {
           email: 'name@example.com',
           company: 'Marketo',
@@ -194,83 +194,27 @@ describe('Marketo', function() {
           },
           customTrait: 'something'
         };
+
         analytics.identify('id', traits, { Marketo: true });
-        analytics.assert(marketo.requestHash.calledWith('name@example.com'));
+
         when(
           function() {
-            return window.mktoMunchkinFunction.called;
+            var callToMkto = window.MktoForms2.loadForm.called;
+            done();
+            return callToMkto;
           },
           function() {
-            // XXX: Trying to figure out why your spec is failing? Throwing
-            // uncaught exceptions? It's this! This assert is probably failing.
-            // I'm ashamed to have touched this code.
-            // TODO: Rewrite this to synchronously stub `requestHash` so we don't
-            // have to do this crap
-            analytics.assert(
-              window.mktoMunchkinFunction.calledWith('associateLead', {
-                Mylittleponyz: 'something',
-                userId: 'id',
-                Company: 'Marketo',
-                Email: 'name@example.com',
-                FirstName: 'Prateek',
-                LastName: 'Srivastava',
-                Phone: '123-456-7890',
-                Fax: '555-555-5555',
-                City: 'San Francisco',
-                Country: 'USA',
-                PostalCode: '94103',
-                State: 'California',
-                anonymousId: 'fc42baa7-6aa4-4500-9ebb-0548762a6ac8'
-              })
-            );
+            var callToMkto = window.MktoForms2.whenReady.called;
             done();
-          }
-        );
-      });
-
-      it('should call window.mktoMunchkinFunction with string address', function(done) {
-        analytics.identify(
-          'name@example.com',
-          { address: 'SF, CA, USA' },
-          { Marketo: true }
-        );
-        when(
-          function() {
-            return window.mktoMunchkinFunction.called;
+            return callToMkto;
           },
           function() {
-            // XXX: Trying to figure out why your spec is failing? Throwing
-            // uncaught exceptions? It's this! This assert is probably failing.
-            // I'm ashamed to have touched this code.
-            // TODO: Rewrite this to synchronously stub `requestHash` so we don't
-            // have to do this crap
-            analytics.assert(
-              window.mktoMunchkinFunction.calledWith('associateLead', {
-                userId: 'name@example.com',
-                Address: 'SF, CA, USA',
-                Email: 'name@example.com',
-                anonymousId: 'fc42baa7-6aa4-4500-9ebb-0548762a6ac8'
-              })
-            );
+            analytics.called(marketo.setupAndSubmitForm, traits, form);
+            analytics.called(form.submit);
             done();
           }
         );
       });
     });
-
-    describe('#emailHashUrl', function() {
-      it('should return the proper url', function() {
-        var email = 'email@domain.com';
-        var url = marketo.emailHashUrl(email);
-        assert.equal(
-          url,
-          fmt(
-            'https://api.segment.io/integrations/marketo/v1/%s/%s/hash-v2',
-            options.projectId,
-            email
-          )
-        );
-      });
-    });
   });
 });