diff --git a/lib/node-http-proxy/http-proxy.js b/lib/node-http-proxy/http-proxy.js
index 3306defcc..924ef0e23 100644
--- a/lib/node-http-proxy/http-proxy.js
+++ b/lib/node-http-proxy/http-proxy.js
@@ -235,10 +235,10 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
     }
 
     if ((response.statusCode === 301) || (response.statusCode === 302)) {
-      if (self.source.https && !self.target.https) {
+      if (self.source.https && !self.target.https && response.headers.location != null) {
         response.headers.location = response.headers.location.replace(/^http\:/, 'https:');
       }
-      if (self.target.https && !self.source.https) {
+      if (self.target.https && !self.source.https && response.headers.location != null) {
         response.headers.location = response.headers.location.replace(/^https\:/, 'http:');
       }
     }