diff --git a/lib/datasource.js b/lib/datasource.js
index be663cbf..254fca15 100644
--- a/lib/datasource.js
+++ b/lib/datasource.js
@@ -398,12 +398,6 @@ DataSource.prototype.defineRelations = function(modelClass, relations) {
  * @param settings
  */
 DataSource.prototype.setupDataAccess = function (modelClass, settings) {
-// add data access objects
-    this.mixin(modelClass);
-
-    var relations = settings.relationships || settings.relations;
-    this.defineRelations(modelClass, relations);
-
     if (this.connector && this.connector.define) {
         // pass control to connector
         this.connector.define({
@@ -412,6 +406,13 @@ DataSource.prototype.setupDataAccess = function (modelClass, settings) {
             settings: settings
         });
     }
+
+    // add data access objects
+    this.mixin(modelClass);
+
+    var relations = settings.relationships || settings.relations;
+    this.defineRelations(modelClass, relations);
+
 };
 
 /**
diff --git a/lib/model-builder.js b/lib/model-builder.js
index 9a935702..a0914db5 100644
--- a/lib/model-builder.js
+++ b/lib/model-builder.js
@@ -5,6 +5,7 @@
 var inflection = require('inflection');
 var EventEmitter = require('events').EventEmitter;
 var util = require('util');
+var assert = require('assert');
 var DefaultModelBaseClass = require('./model.js');
 var List = require('./list.js');
 var ModelDefinition = require('./model-definition.js');
@@ -47,6 +48,13 @@ util.inherits(ModelBuilder, EventEmitter);
 // Create a default instance
 ModelBuilder.defaultInstance = new ModelBuilder();
 
+function isModelClass(cls) {
+    if(!cls) {
+        return false;
+    }
+    return cls.prototype instanceof DefaultModelBaseClass;
+}
+
 /**
  * Define a model class
  *
@@ -82,7 +90,6 @@ ModelBuilder.prototype.define = function defineClass(className, properties, sett
     var dataSource = this;
     var args = slice.call(arguments);
     var pluralName = settings && settings.plural;
-    var ModelBaseClass = parent || DefaultModelBaseClass;
 
     if (!className) {
         throw new Error('Class name required');
@@ -104,6 +111,18 @@ ModelBuilder.prototype.define = function defineClass(className, properties, sett
         settings.strict = false;
     }
 
+    // Set up the base model class
+    var ModelBaseClass = parent || DefaultModelBaseClass;
+    var baseClass = settings.base || settings['super'];
+    if(baseClass) {
+        if(isModelClass(baseClass)) {
+            ModelBaseClass = baseClass;
+        } else {
+            ModelBaseClass = this.models[baseClass];
+            assert(ModelBaseClass, 'Base model is not found: ' + baseClass);
+        }
+    }
+
     // Check if there is a unresolved model with the same name
     var ModelClass = this.models[className];
 
diff --git a/test/loopback-dl.test.js b/test/loopback-dl.test.js
index 1537132d..9a3e8bc7 100644
--- a/test/loopback-dl.test.js
+++ b/test/loopback-dl.test.js
@@ -418,6 +418,31 @@ describe('DataSource define model', function () {
 
 });
 
+describe('Load models with base', function () {
+  it('should set up base class', function (done) {
+    var ds = new ModelBuilder();
+
+    var User = ds.define('User', {name: String});
+
+    User.staticMethod = function staticMethod() {};
+    User.prototype.instanceMethod = function instanceMethod() {};
+
+    var Customer = ds.define('Customer', {vip: Boolean}, {base: 'User'});
+
+    assert(Customer.prototype instanceof User);
+    assert(Customer.staticMethod === User.staticMethod);
+    assert(Customer.prototype.instanceMethod === User.prototype.instanceMethod);
+
+
+    try {
+      var Customer1 = ds.define('Customer1', {vip: Boolean}, {base: 'User1'});
+    } catch(e) {
+      assert(e);
+    }
+
+    done();
+  });
+});
 
 describe('Load models with relations', function () {
     it('should set up relations', function (done) {