diff --git a/include/wx/event.h b/include/wx/event.h
index 4e9ecf9b82..d70beb59e6 100644
--- a/include/wx/event.h
+++ b/include/wx/event.h
@@ -493,7 +493,7 @@ private:
 // Backwards compatibility for wxCommandEvent::m_commandString, will lead to compilation errors in some cases of usage
 class WXDLLIMPEXP_CORE wxCommandEvent;
 
-class wxCommandEventStringHelper
+class WXDLLIMPEXP_CORE wxCommandEventStringHelper
 {
 public:
     wxCommandEventStringHelper(wxCommandEvent * evt)