diff -Naur a/src/microhttpd/connection.c b/src/microhttpd/connection.c
--- a/src/microhttpd/connection.c	2016-04-20 11:35:50.259534537 +0000
+++ b/src/microhttpd/connection.c	2016-04-20 11:29:46.291569583 +0000
@@ -733,8 +733,7 @@
   {
     if (NULL == end)
       return MHD_YES;
-    if ( (MHD_str_equal_caseless_ (end, "close")) ||
-         (MHD_str_equal_caseless_ (end, "upgrade")) )
+    if ( (MHD_str_equal_caseless_ (end, "close")) )
       return MHD_NO;
    return MHD_YES;
   }