diff --git a/include/wx/generic/datectrl.h b/include/wx/generic/datectrl.h
index de60cabf4a..e1b5ad3563 100644
--- a/include/wx/generic/datectrl.h
+++ b/include/wx/generic/datectrl.h
@@ -12,9 +12,9 @@
 #ifndef _WX_GENERIC_DATECTRL_H_
 #define _WX_GENERIC_DATECTRL_H_
 
-#include "wx/calctrl.h"
-#include "wx/combo.h"
+class WXDLLIMPEXP_FWD_CORE wxComboCtrl;
 
+class WXDLLIMPEXP_FWD_ADV wxCalendarCtrl;
 class WXDLLIMPEXP_FWD_ADV wxCalendarComboPopup;
 
 class WXDLLIMPEXP_ADV wxDatePickerCtrlGeneric : public wxDatePickerCtrlBase
diff --git a/src/generic/datectlg.cpp b/src/generic/datectlg.cpp
index 5d4e6b0614..a862229255 100644
--- a/src/generic/datectlg.cpp
+++ b/src/generic/datectlg.cpp
@@ -34,9 +34,10 @@
     #include "wx/valtext.h"
 #endif
 
-#include "wx/datectrl.h"
-#include "wx/generic/datectrl.h"
+#include "wx/calctrl.h"
+#include "wx/combo.h"
 
+#include "wx/datectrl.h"
 
 // ----------------------------------------------------------------------------
 // constants