diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index 3af18a051c..f973c34425 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -128,6 +128,15 @@ Agent.prototype.getName = function(options) {
 };
 
 Agent.prototype.addRequest = function(req, options) {
+  // Legacy API: addRequest(req, host, port, path)
+  if (typeof options === 'string') {
+    options = {
+      host: options,
+      port: arguments[2],
+      path: arguments[3]
+    };
+  }
+
   var host = options.host;
   var port = options.port;
   var localAddress = options.localAddress;