diff --git a/lib/http-proxy/passes/web-outgoing.js b/lib/http-proxy/passes/web-outgoing.js
index ad8b8d0c8..20b0f3cba 100644
--- a/lib/http-proxy/passes/web-outgoing.js
+++ b/lib/http-proxy/passes/web-outgoing.js
@@ -83,7 +83,7 @@ var redirectRegex = /^30(1|2|7|8)$/;
   function writeHeaders(req, res, proxyRes) {
     Object.keys(proxyRes.headers).forEach(function(key) {
       if(proxyRes.headers[key] != undefined){
-        res.setHeader(key, proxyRes.headers[key]);
+        res.setHeader(String(key).trim(), proxyRes.headers[key]);
       }
     });
   },