diff --git a/src/windows-emulator/memory_permission_ext.hpp b/src/windows-emulator/memory_permission_ext.hpp
index 63427929..1ea95426 100644
--- a/src/windows-emulator/memory_permission_ext.hpp
+++ b/src/windows-emulator/memory_permission_ext.hpp
@@ -90,6 +90,7 @@ struct nt_memory_permission
     nt_memory_permission& operator=(memory_permission const& y)
     {
         this->common = y;
+        this->extended = memory_permission_ext::none;
         return *this;
     }