diff --git a/lib/node-http-proxy/routing-proxy.js b/lib/node-http-proxy/routing-proxy.js
index 77b4a8d24..4e4fc32a5 100644
--- a/lib/node-http-proxy/routing-proxy.js
+++ b/lib/node-http-proxy/routing-proxy.js
@@ -180,8 +180,8 @@ RoutingProxy.prototype.proxyRequest = function (req, res, options) {
     options.host = location.host;
   }
   
-  var key = options.host + ':' + options.port,
-      proxy;
+  var key = this._getKey(options),
+    proxy;
   
   if (!this.proxies[key]) {
     this.add(options);
@@ -218,8 +218,8 @@ RoutingProxy.prototype.proxyWebSocketRequest = function (req, socket, head, opti
     options.host = location.host;
   }
   
-  var key = options.host + ':' + options.port,
-      proxy;
+  var key = this._getKey(options),
+    proxy;
 
   if (!this.proxies[key]) {
     this.add(options);