diff --git a/src/OptionHandlerFactory.cc b/src/OptionHandlerFactory.cc
index 82e92e0a..197aa243 100644
--- a/src/OptionHandlerFactory.cc
+++ b/src/OptionHandlerFactory.cc
@@ -790,6 +790,7 @@ OptionHandlerFactory::createOptionHandlers()
     op->addTag(TAG_HTTP);
     op->setInitialOption(true);
     op->setChangeGlobalOption(true);
+    op->setChangeOptionForReserved(true);
     handlers.push_back(op);
   }
   {