diff --git a/src/ws_engine.cpp b/src/ws_engine.cpp
index d3b02bee..cb5510e1 100644
--- a/src/ws_engine.cpp
+++ b/src/ws_engine.cpp
@@ -454,17 +454,17 @@ bool zmq::ws_engine_t::server_handshake ()
                         _header_upgrade_websocket =
                           strcasecmp ("websocket", _header_value) == 0;
                     else if (strcasecmp ("connection", _header_name) == 0){
-			char *element = strtok (_header_value, ",");
-			while (element != NULL){
-			    while (*element == ' ')
-			        element++;
+                        char *element = strtok (_header_value, ",");
+                        while (element != NULL){
+                            while (*element == ' ')
+                                element++;
                             if (strcasecmp ("upgrade", element) == 0){
-			        _header_connection_upgrade = true;
-				break;
-			    }
-			    element = strtok (NULL, ",");
-			}
-		    }
+                                _header_connection_upgrade = true;
+                                break;
+                            }
+                            element = strtok (NULL, ",");
+                        }
+                    }
                     else if (strcasecmp ("Sec-WebSocket-Key", _header_name)
                              == 0)
                         strcpy_s (_websocket_key, _header_value);