diff --git a/components/widgets/windowcaption.hpp b/components/widgets/windowcaption.hpp
index bdd4c0a2e..b45da2d1c 100644
--- a/components/widgets/windowcaption.hpp
+++ b/components/widgets/windowcaption.hpp
@@ -23,6 +23,7 @@ namespace Gui
     private:
         MyGUI::Widget* mLeft;
         MyGUI::Widget* mRight;
+        MyGUI::Widget* mClient;
 
         void align();
     };