diff --git a/lib/express-session-mongo.js b/lib/express-session-mongo.js
index 94bbeaf..11c3539 100644
--- a/lib/express-session-mongo.js
+++ b/lib/express-session-mongo.js
@@ -14,7 +14,7 @@ var mongo = require('mongodb'),
 var MongoStore = function(options) {
     options = options || {};
     Session.Store.call(this, options);
-    
+
     // Default reapInterval to 10 minutes
     this.reapInterval = options.reapInterval || 600000;
 
@@ -23,10 +23,11 @@ var MongoStore = function(options) {
             self.reap(self.maxAge);
         }, this.reapInterval, this);
     }
-    
+
     var server,
         dbName = (options.db) ? options.db : 'express-sessions',
         ip = (options.ip) ? options.ip : '127.0.0.1',
+        useNative = (options.native !== undefined) ? options.native : true,
         port = (options.port) ? options.port : 27017;
 
     this._collection = (options.collection) ? options.collection : 'sessions';
@@ -37,9 +38,9 @@ var MongoStore = function(options) {
         server= new Server(ip, port, {auto_reconnect: true}, {});
     }
 
-    this._db = new Db( dbName, server, { native_parser:true });
+    this._db = new Db( dbName, server, { native_parser: useNative });
     this._db.open(function(db) {});
-    
+
 }
 
 util.inherits(MongoStore, Session.Store);
@@ -65,7 +66,7 @@ MongoStore.prototype.set = function(sid, sess, fn) {
                 }
                 collection[method](sess, function(err, document) {
                     if (err) {
-                    } else { 
+                    } else {
                         fn && fn(null, sess);
                     }
                 });
@@ -79,7 +80,7 @@ MongoStore.prototype.get = function(sid, fn) {
         collection.findOne({ _sessionid: sid }, function(err, session_data) {
             if (err) {
                 fn && fn(error);
-            } else { 
+            } else {
                 if (session_data) {
                     session_data = cleanSessionData(session_data);
                 }
@@ -136,7 +137,7 @@ var cleanSessionData = function(json) {
                 data[i] = data[i].toNumber();
             }
         }
-        
+
     }
     return data;
 }