diff --git a/tests/integration/components/modifier-manager-test.js b/tests/integration/components/modifier-manager-test.js
index f84fc85..224b362 100644
--- a/tests/integration/components/modifier-manager-test.js
+++ b/tests/integration/components/modifier-manager-test.js
@@ -18,6 +18,15 @@ module('Integration | Component | modifier-manager', function(hooks) {
     };
   });
 
+  module('setModifierManager', function() {
+    test('it returns the provided object', function(assert) {
+      let expected = Object.freeze({});
+      let actual = Ember._setModifierManager(() => {}, expected);
+
+      assert.strictEqual(actual, expected, 'the passed in object was returned');
+    });
+  });
+
   module('installModifier', function(hooks) {
     hooks.beforeEach(function() {
       class DidInsertModifier {}
diff --git a/vendor/ember-modifier-manager-polyfill.js b/vendor/ember-modifier-manager-polyfill.js
index d058a32..a694dfb 100644
--- a/vendor/ember-modifier-manager-polyfill.js
+++ b/vendor/ember-modifier-manager-polyfill.js
@@ -11,6 +11,7 @@ import { lte, gte } from 'ember-compatibility-helpers';
   let MODIFIER_MANAGERS = new WeakMap();
   Ember._setModifierManager = function Polyfilled_setModifierManager(managerFactory, modifier) {
     MODIFIER_MANAGERS.set(modifier, managerFactory);
+    return modifier;
   };
 
   let getModifierManager = obj => {