diff --git a/lib/datasource.js b/lib/datasource.js
index 08c82644..cb9e96fb 100644
--- a/lib/datasource.js
+++ b/lib/datasource.js
@@ -165,7 +165,7 @@ function DataSource(name, settings, modelBuilder) {
   }.bind(this));
 
   // define DataAccessObject.prototype methods
-  Object.keys(dao.prototype).forEach(function(name) {
+  Object.keys(dao.prototype || []).forEach(function(name) {
     var fn = dao.prototype[name];
     this.DataAccessObject.prototype[name] = fn;
     if (typeof fn === 'function') {
@@ -2541,6 +2541,7 @@ DataSource.prototype.ready = function(obj, args) {
  * @param {Function} [cb] Callback function
  */
 DataSource.prototype.ping = function(cb) {
+  cb = cb || utils.createPromiseCallback();
   var self = this;
   if (self.connector.ping) {
     this.connector.ping(cb);
@@ -2552,6 +2553,7 @@ DataSource.prototype.ping = function(cb) {
       cb(err);
     });
   }
+  return cb.promise;
 };
 
 /*! The hidden property call is too expensive so it is not used that much