diff --git a/lib/cors-anywhere.js b/lib/cors-anywhere.js
index 287f24d..030ec1d 100644
--- a/lib/cors-anywhere.js
+++ b/lib/cors-anywhere.js
@@ -74,41 +74,27 @@ function proxyRequest(req, res, proxy, full_url, isRequestedOverHttps, proxyOpti
   // Let the "Host" header be the host part of the path (including port, if specified).
   req.headers.host = full_url.split('/', 3)[2];
 
-  // Hook res.writeHead
-  var res_writeHead = res.writeHead;
-
-  res.writeHead = function(statusCode, reasonPhrase, headers) {
-    if (typeof reasonPhrase === 'object') {
-      headers = reasonPhrase;
-      reasonPhrase = undefined;
-    }
-    headers = withCORS(headers || {}, req);
-    withCORS(headers, req);
+  // "Allow observer to modify headers or abort response"
+  // https://github.com/nodejitsu/node-http-proxy/blob/ebbba73e/lib/node-http-proxy/http-proxy.js#L321-L322
+  proxy.on('proxyResponse', function(req, res, response) {
+    withCORS(response.headers, req);
 
+    var statusCode = response.statusCode;
     // Handle redirects
     if (statusCode === 301 || statusCode === 302 || statusCode === 303 || statusCode === 307 || statusCode === 308) {
-      var locationHeader = headers['location'] || res.getHeader('location');
+      var locationHeader = response.headers['location'];
       if (locationHeader) {
-        res.removeHeader('location');
-        headers['location'] = (isRequestedOverHttps ? 'https://' : 'http://') + realHost + '/' +
-                               url.resolve(full_url, locationHeader);
+        response.headers['location'] = (isRequestedOverHttps ? 'https://' : 'http://') + realHost + '/' +
+                                       url.resolve(full_url, locationHeader);
       }
     }
 
     // Don't slip through cookies
-    delete headers['set-cookie'];
-    delete headers['set-cookie2'];
-    res.removeHeader('set-cookie');
-    res.removeHeader('set-cookie2');
+    delete response.headers['set-cookie'];
+    delete response.headers['set-cookie2'];
 
-    headers['x-request-url'] = full_url;
-
-    if (reasonPhrase) {
-      return res_writeHead.call(res, statusCode, reasonPhrase, headers);
-    } else {
-      return res_writeHead.call(res, statusCode, headers);
-    }
-  };
+    response.headers['x-request-url'] = full_url;
+  });
 
   // Start proxying the request
   proxy.proxyRequest(req, res, proxyOptions);