diff --git a/lib/node-http-proxy/http-proxy.js b/lib/node-http-proxy/http-proxy.js
index a26a68c..7e97041 100644
--- a/lib/node-http-proxy/http-proxy.js
+++ b/lib/node-http-proxy/http-proxy.js
@@ -247,7 +247,8 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
       delete response.headers['transfer-encoding'];
     }
 
-    if ((response.statusCode === 301) || (response.statusCode === 302)) {
+    if ((response.statusCode === 301) || (response.statusCode === 302)
+      && typeof response.headers.location !== 'undefined') {
       if (self.source.https && !self.target.https) {
         response.headers.location = response.headers.location.replace(/^http\:/, 'https:');
       }