diff --git a/src/common/sizer.cpp b/src/common/sizer.cpp
index 89d60066b9..2727d57d1c 100644
--- a/src/common/sizer.cpp
+++ b/src/common/sizer.cpp
@@ -235,7 +235,10 @@ void wxSizerItem::SetDimension( wxPoint pos, wxSize size )
 void wxSizerItem::DeleteWindows()
 {
     if (m_window)
+    {
          m_window->Destroy();
+         m_window = NULL;
+    }
 
     if (m_sizer)
         m_sizer->DeleteWindows();