diff --git a/lib/connection-pool.js b/lib/connection-pool.js
index 3c0af44..6146a47 100644
--- a/lib/connection-pool.js
+++ b/lib/connection-pool.js
@@ -51,10 +51,10 @@ ConnectionPool.prototype.requestConnection = function(callback) {
   var self = this;
   this.pool.acquire(function(err, connection) {
     if(err) {
-      
+      callback(err, undefined); 
     }
     else {
-      callback(connection);
+      callback(undefined, connection);
       connection.emit('connect');
     }
   });