diff --git a/addon/adapters/json-api.js b/addon/adapters/json-api.js
index 7fd59392376..e0cdd14d283 100644
--- a/addon/adapters/json-api.js
+++ b/addon/adapters/json-api.js
@@ -5,6 +5,7 @@
 import Ember from 'ember';
 import RESTAdapter from "ember-data/adapters/rest";
 import isEnabled from 'ember-data/-private/features';
+import { deprecate } from 'ember-data/-private/debug';
 
 /**
   @class JSONAPIAdapter
@@ -99,7 +100,7 @@ var JSONAPIAdapter = RESTAdapter.extend({
     @return {Promise} promise
   */
   findMany(store, type, ids, snapshots) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       return this._super(...arguments);
     } else {
       var url = this.buildURL(type.modelName, ids, snapshots, 'findMany');
@@ -126,7 +127,7 @@ var JSONAPIAdapter = RESTAdapter.extend({
     @return {Promise} promise
   */
   updateRecord(store, type, snapshot) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       return this._super(...arguments);
     } else {
       var data = {};
@@ -139,6 +140,26 @@ var JSONAPIAdapter = RESTAdapter.extend({
 
       return this.ajax(url, 'PATCH', { data: data });
     }
+  },
+
+  _hasCustomizedAjax() {
+    if (this.ajax !== JSONAPIAdapter.prototype.ajax) {
+      deprecate('JSONAPIAdapter#ajax has been deprecated please use. `methodForRequest`, `urlForRequest`, `headersForRequest` or `dataForRequest` instead.', false, {
+        id: 'ds.json-api-adapter.ajax',
+        until: '3.0.0'
+      });
+      return true;
+    }
+
+    if (this.ajaxOptions !== JSONAPIAdapter.prototype.ajaxOptions) {
+      deprecate('JSONAPIAdapterr#ajaxOptions has been deprecated please use. `methodForRequest`, `urlForRequest`, `headersForRequest` or `dataForRequest` instead.', false, {
+        id: 'ds.json-api-adapter.ajax-options',
+        until: '3.0.0'
+      });
+      return true;
+    }
+
+    return false;
   }
 });
 
diff --git a/addon/adapters/rest.js b/addon/adapters/rest.js
index ebfc66aede8..91d82a70d26 100644
--- a/addon/adapters/rest.js
+++ b/addon/adapters/rest.js
@@ -17,7 +17,7 @@ import {
 } from 'ember-data/adapters/errors';
 import BuildURLMixin from "ember-data/-private/adapters/build-url-mixin";
 import isEnabled from 'ember-data/-private/features';
-import { runInDebug, warn } from 'ember-data/-private/debug';
+import { runInDebug, warn, deprecate } from 'ember-data/-private/debug';
 import parseResponseHeaders from 'ember-data/-private/utils/parse-response-headers';
 
 const {
@@ -417,7 +417,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     @return {Promise} promise
   */
   findRecord(store, type, id, snapshot) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, type, id, snapshot,
         requestType: 'findRecord'
@@ -449,7 +449,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
   findAll(store, type, sinceToken, snapshotRecordArray) {
     const query = this.buildQuery(snapshotRecordArray);
 
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, type, sinceToken, query,
         snapshots: snapshotRecordArray,
@@ -486,7 +486,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     @return {Promise} promise
   */
   query(store, type, query) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, type, query,
         requestType: 'query'
@@ -522,7 +522,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     @return {Promise} promise
   */
   queryRecord(store, type, query) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, type, query,
         requestType: 'queryRecord'
@@ -574,7 +574,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     @return {Promise} promise
   */
   findMany(store, type, ids, snapshots) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, type, ids, snapshots,
         requestType: 'findMany'
@@ -623,7 +623,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     @return {Promise} promise
   */
   findHasMany(store, snapshot, url, relationship) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, snapshot, url, relationship,
         requestType: 'findHasMany'
@@ -676,7 +676,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     @return {Promise} promise
   */
   findBelongsTo(store, snapshot, url, relationship) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, snapshot, url, relationship,
         requestType: 'findBelongsTo'
@@ -709,7 +709,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     @return {Promise} promise
   */
   createRecord(store, type, snapshot) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, type, snapshot,
         requestType: 'createRecord'
@@ -744,7 +744,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     @return {Promise} promise
   */
   updateRecord(store, type, snapshot) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, type, snapshot,
         requestType: 'updateRecord'
@@ -776,7 +776,7 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     @return {Promise} promise
   */
   deleteRecord(store, type, snapshot) {
-    if (isEnabled('ds-improved-ajax')) {
+    if (isEnabled('ds-improved-ajax') && !this._hasCustomizedAjax()) {
       const request = this._requestFor({
         store, type, snapshot,
         requestType: 'deleteRecord'
@@ -1169,6 +1169,26 @@ var RESTAdapter = Adapter.extend(BuildURLMixin, {
     }
 
     return query;
+  },
+
+  _hasCustomizedAjax() {
+    if (this.ajax !== RESTAdapter.prototype.ajax) {
+      deprecate('RESTAdapter#ajax has been deprecated please use. `methodForRequest`, `urlForRequest`, `headersForRequest` or `dataForRequest` instead.', false, {
+        id: 'ds.rest-adapter.ajax',
+        until: '3.0.0'
+      });
+      return true;
+    }
+
+    if (this.ajaxOptions !== RESTAdapter.prototype.ajaxOptions) {
+      deprecate('RESTAdapter#ajaxOptions has been deprecated please use. `methodForRequest`, `urlForRequest`, `headersForRequest` or `dataForRequest` instead.', false, {
+        id: 'ds.rest-adapter.ajax-options',
+        until: '3.0.0'
+      });
+      return true;
+    }
+
+    return false;
   }
 });
 
diff --git a/config/features.json b/config/features.json
index 79ca3c55c68..16a1fe42265 100644
--- a/config/features.json
+++ b/config/features.json
@@ -1,10 +1,10 @@
 {
-  "ds-boolean-transform-allow-null": null,
-  "ds-improved-ajax": null,
+  "ds-boolean-transform-allow-null": true,
+  "ds-improved-ajax": true,
   "ds-pushpayload-return": null,
   "ds-serialize-ids-and-types": true,
   "ds-extended-errors": null,
-  "ds-links-in-record-array": null,
+  "ds-links-in-record-array": true,
   "ds-overhaul-references": null,
   "ds-payload-type-hooks": null,
   "ds-check-should-serialize-relationships": null,
diff --git a/tests/integration/adapter/rest-adapter-test.js b/tests/integration/adapter/rest-adapter-test.js
index d2ab0e33da5..cc4f97f196a 100644
--- a/tests/integration/adapter/rest-adapter-test.js
+++ b/tests/integration/adapter/rest-adapter-test.js
@@ -2593,3 +2593,44 @@ testInDebug("warns when an empty response is returned, though a valid stringifie
 
   assert.expectWarning("The server returned an empty string for POST /posts, which cannot be parsed into a valid JSON. Return either null or {}.");
 });
+
+
+testInDebug("The RESTAdapter should use `ajax` with a deprecation message when it is overridden by the user.", function(assert) {
+  assert.expect(2)
+
+  adapter.ajax = function(url, verb, hash) {
+    assert.ok(true, 'The ajax method should be called when it is overridden');
+    return { posts: { id: 1, name: "Rails is omakase" } };
+  };
+
+  assert.expectDeprecation(function() {
+    run(function() {
+      store.findRecord('post', 1);
+    });
+  }, /RESTAdapter#ajax has been deprecated/)
+});
+
+
+testInDebug("The RESTAdapter should use `ajaxOptions` with a deprecation message when it is overridden by the user.", function(assert) {
+  assert.expect(2)
+
+  adapter._ajaxRequest = function(hash) {
+    var jqXHR = {
+      status: 200,
+      getAllResponseHeaders() { return ''; }
+    };
+    hash.success({ posts: { id: 1, name: "Rails is omakase" } }, 'OK', jqXHR);
+  }
+
+  var oldAjaxOptions = adapter.ajaxOptions;
+  adapter.ajaxOptions = function() {
+    assert.ok(true, 'The ajaxOptions method should be called when it is overridden');
+    return oldAjaxOptions.apply(this, arguments);
+  };
+
+  assert.expectDeprecation(function() {
+    run(function() {
+      store.findRecord('post', 1);
+    });
+  }, /RESTAdapter#ajaxOptions has been deprecated/)
+});