diff --git a/include/wx/ribbon/art.h b/include/wx/ribbon/art.h
index f0cc1596e7..d52796b115 100644
--- a/include/wx/ribbon/art.h
+++ b/include/wx/ribbon/art.h
@@ -19,6 +19,9 @@
 #include <wx/brush.h>
 #include <wx/pen.h>
 
+class WXDLLIMPEXP_FWD_CORE wxDC;
+class WXDLLIMPEXP_FWD_CORE wxWindow;
+
 enum wxRibbonArtSetting
 {
     wxRIBBON_ART_TAB_SEPARATION_SIZE,
diff --git a/src/ribbon/art_aui.cpp b/src/ribbon/art_aui.cpp
index bd97d9f211..c21ac1cadb 100644
--- a/src/ribbon/art_aui.cpp
+++ b/src/ribbon/art_aui.cpp
@@ -30,6 +30,8 @@
 
 #ifdef __WXMSW__
 #include "wx/msw/private.h"
+#elif defined(__WXMAC__)
+#include "wx/osx/private.h"
 #endif
 
 wxRibbonAUIArtProvider::wxRibbonAUIArtProvider()