diff --git a/lib/connection-pool.js b/lib/connection-pool.js
index ba169da..f6fe152 100755
--- a/lib/connection-pool.js
+++ b/lib/connection-pool.js
@@ -3,9 +3,9 @@ var Connection = require('tedious').Connection;
 var EventEmitter = require('events').EventEmitter;
 var util = require('util');
 
-Connection.prototype.release = function() {
+function release() {
     this.pool.release(this);
-};
+}
 
 var PENDING = 0;
 var FREE = 1;
@@ -63,6 +63,7 @@ function createConnection(pooled) {
 
     this.log('creating connection: ' + cid);
     var connection = new Connection(this.connectionConfig);
+    connection.release = release;
     connection.pool = this;
     if (pooled) {
         pooled.id = cid++;
@@ -113,7 +114,7 @@ function createConnection(pooled) {
 
     connection.on('error', handleError);
 
-    var endHandler = function () {
+    endHandler = function () {
         self.log('connection ended: ' + pooled.id);
         if (self.drained) //pool has been drained
             return;