diff --git a/lib/node-http-proxy/http-proxy.js b/lib/node-http-proxy/http-proxy.js
index ffd5c957d..079488aaf 100644
--- a/lib/node-http-proxy/http-proxy.js
+++ b/lib/node-http-proxy/http-proxy.js
@@ -237,7 +237,8 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
   // don't revert this without documenting it!
   //
   if (this.changeOrigin) {
-    outgoing.headers.host = this.target.host + ':' + this.target.port;
+		var port = (this.target.port-80==0?"":":"+this.target.port);
+    outgoing.headers.host = this.target.host + port;
   }
   
   //