diff --git a/lib/http-proxy/passes/ws-incoming.js b/lib/http-proxy/passes/ws-incoming.js
index 7673fe067..db74729b7 100644
--- a/lib/http-proxy/passes/ws-incoming.js
+++ b/lib/http-proxy/passes/ws-incoming.js
@@ -83,9 +83,13 @@ var passes = exports;
 
     if (head && head.length) socket.unshift(head);
 
+    var outgoing = common.setupOutgoing(options.ssl || {}, options, req);
+    
+    // Force "connection": "upgrade" in header (outgoing default to "close")
+    outgoing.headers.connection = 'upgrade';
 
     var proxyReq = (~['https:', 'wss:'].indexOf(options.target.protocol) ? https : http).request(
-      common.setupOutgoing(options.ssl || {}, options, req)
+      outgoing
     );
     // Error Handler
     proxyReq.on('error', onOutgoingError);