diff --git a/source/gui/detail/basic_window.cpp b/source/gui/detail/basic_window.cpp
index 0a5542fe..873a32ae 100644
--- a/source/gui/detail/basic_window.cpp
+++ b/source/gui/detail/basic_window.cpp
@@ -216,6 +216,8 @@ namespace nana
 					switch(categ)
 					{
 					case category::flags::root:
+						attribute.root = new attr_root_tag;
+						delete attribute.root;
 						attribute.root = new attr_root_tag;
 						std::cout<<"basic_window: create attr root "<<attribute.root<<std::endl;
 						break;