diff --git a/lib/server/proxy-server.js b/lib/server/proxy-server.js
index 8ade4749b..4a89961eb 100644
--- a/lib/server/proxy-server.js
+++ b/lib/server/proxy-server.js
@@ -45,6 +45,11 @@ var ProxyOption = Immutable.Record({
      * with args [proxyRes, req, res]
      */
     proxyRes:     List([]),
+    /**
+     * Functions to be called on proxy response
+     * with args [proxyReq, req, socket, options, head]
+     */
+    proxyReqWs:   List([]),
     errHandler:   undefined,
     url:          Map({}),
     proxyOptions: Map(defaultHttpProxyOptions),
@@ -99,10 +104,11 @@ module.exports = function createProxyServer (bs, scripts) {
     }
 
     /**
-     * Add any user provided functions for proxyReq and proxyRes
+     * Add any user provided functions for proxyReq, proxyReqWs and proxyRes
      */
     applyFns("proxyReq", proxyReq);
     applyFns("proxyRes", proxyRes);
+    applyFns('proxyReqWs', opt.get("proxyReqWs"))
 
     /**
      * Handle Proxy errors