-extern WXDLLIMPEXP_ADV const wxEventType wxEVT_QUERY_LAYOUT_INFO;
-extern WXDLLIMPEXP_ADV const wxEventType wxEVT_CALCULATE_LAYOUT;
+class WXDLLIMPEXP_FWD_ADV wxQueryLayoutInfoEvent;
+class WXDLLIMPEXP_FWD_ADV wxCalculateLayoutEvent;
+
+wxDECLARE_EXPORTED_EVENT( WXDLLIMPEXP_ADV, wxEVT_QUERY_LAYOUT_INFO, wxQueryLayoutInfoEvent );
+wxDECLARE_EXPORTED_EVENT( WXDLLIMPEXP_ADV, wxEVT_CALCULATE_LAYOUT, wxCalculateLayoutEvent );