diff --git a/include/wx/generic/datectrl.h b/include/wx/generic/datectrl.h
index 0c33de5a7b..5e00c21e5e 100644
--- a/include/wx/generic/datectrl.h
+++ b/include/wx/generic/datectrl.h
@@ -15,8 +15,7 @@
 class WXDLLIMPEXP_ADV wxCalendarDateAttr;
 class WXDLLIMPEXP_ADV wxCalendarCtrl;
 class WXDLLIMPEXP_ADV wxCalendarEvent;
-
-#include <wx/popupwin.h>
+class WXDLLIMPEXP_ADV wxPopupWindow;
 
 class WXDLLIMPEXP_ADV wxDatePickerCtrl : public wxDatePickerCtrlBase
 {
diff --git a/src/generic/datectlg.cpp b/src/generic/datectlg.cpp
index 1fb696c719..ef8d9905f2 100644
--- a/src/generic/datectlg.cpp
+++ b/src/generic/datectlg.cpp
@@ -37,6 +37,7 @@
 
 #include "wx/datectrl.h"
 #include "wx/calctrl.h"
+#include "wx/popupwin.h"
 
 // ----------------------------------------------------------------------------
 // constants