diff --git a/lib/tunnel.js b/lib/tunnel.js
index cf28016e2..9e790aed4 100644
--- a/lib/tunnel.js
+++ b/lib/tunnel.js
@@ -34,7 +34,7 @@ var defaultProxyHeaderExclusiveList = [
 ]
 
 function constructProxyHost(uriObject) {
-  var port = uriObject.portA
+  var port = uriObject.port
     , protocol = uriObject.protocol
     , proxyHost = uriObject.hostname + ':'