diff --git a/addon/models/resource.js b/addon/models/resource.js
index 3651043..acfaf02 100644
--- a/addon/models/resource.js
+++ b/addon/models/resource.js
@@ -215,7 +215,7 @@ const Resource = Ember.Object.extend(ResourceOperationsMixin, {
       data.push(identifier);
       if (resource) {
         let resources = this.get(related);
-        if (!resources.contains(resource)) {
+        if (!resources.includes(resource)) {
           resources.pushObject(resource);
         }
       }
diff --git a/blueprints/jsonapi-initializer-test/files/tests/unit/initializers/__name__-test.js b/blueprints/jsonapi-initializer-test/files/tests/unit/initializers/__name__-test.js
index 46a2972..0dc5f8f 100644
--- a/blueprints/jsonapi-initializer-test/files/tests/unit/initializers/__name__-test.js
+++ b/blueprints/jsonapi-initializer-test/files/tests/unit/initializers/__name__-test.js
@@ -25,7 +25,7 @@ test('it registers <%= resource %> factory: model, injects into: service, serial
   <%= classifiedModuleName %>Initializer.initialize(registry, application);
 
   let registered = Ember.A(factories.mapBy('name'));
-  assert.ok(registered.contains('model:<%= entity %>'), 'model:<%= entity %> registered');
+  assert.ok(registered.includes('model:<%= entity %>'), 'model:<%= entity %> registered');
   let msg = '<%= resource %> injected into service:store';
   assert.equal(injections.findBy('factory', 'service:store').property, '<%= resource %>', msg);
   msg = 'serializer injected into service:<%= resource %>';
diff --git a/package.json b/package.json
index 9d72bfa..ee4adcf 100644
--- a/package.json
+++ b/package.json
@@ -65,6 +65,7 @@
   "dependencies": {
     "ember-cli-babel": "^5.1.7",
     "ember-inflector": "^1.9.1",
+    "ember-runtime-enumerable-includes-polyfill": "^1.0.2",
     "inflection": "~1.7.1",
     "lodash": "~3.10.1"
   },
diff --git a/tests/unit/initializers/store-test.js b/tests/unit/initializers/store-test.js
index d4d46b2..367533a 100644
--- a/tests/unit/initializers/store-test.js
+++ b/tests/unit/initializers/store-test.js
@@ -25,7 +25,7 @@ test('it registers service and injects into route and controller', function(asse
   initialize(registry, application);
 
   let registered = Ember.A(factories.mapBy('name'));
-  assert.ok(registered.contains('service:store'), 'service:briefs registered');
+  assert.ok(registered.includes('service:store'), 'service:briefs registered');
 
   let injection = injections.findBy('factory', 'route');
   assert.equal(injection.property, 'store', 'store injected into route factory');