diff --git a/src/ws_engine.cpp b/src/ws_engine.cpp
index a239330c..d3b02bee 100644
--- a/src/ws_engine.cpp
+++ b/src/ws_engine.cpp
@@ -453,9 +453,18 @@ bool zmq::ws_engine_t::server_handshake ()
                     if (strcasecmp ("upgrade", _header_name) == 0)
                         _header_upgrade_websocket =
                           strcasecmp ("websocket", _header_value) == 0;
-                    else if (strcasecmp ("connection", _header_name) == 0)
-                        _header_connection_upgrade =
-                          strcasecmp ("upgrade", _header_value) == 0;
+                    else if (strcasecmp ("connection", _header_name) == 0){
+			char *element = strtok (_header_value, ",");
+			while (element != NULL){
+			    while (*element == ' ')
+			        element++;
+                            if (strcasecmp ("upgrade", element) == 0){
+			        _header_connection_upgrade = true;
+				break;
+			    }
+			    element = strtok (NULL, ",");
+			}
+		    }
                     else if (strcasecmp ("Sec-WebSocket-Key", _header_name)
                              == 0)
                         strcpy_s (_websocket_key, _header_value);