diff --git a/include/wx/systhemectrl.h b/include/wx/systhemectrl.h
index 0b9a9ab6ba..8af2d5d9c1 100644
--- a/include/wx/systhemectrl.h
+++ b/include/wx/systhemectrl.h
@@ -12,6 +12,10 @@
 
 #include "wx/defs.h"
 
+#if defined(__WXMSW__) && !defined(__WXUNIVERSAL__)
+    #define wxHAS_SYSTEM_THEMED_CONTROL
+#endif
+
 class WXDLLIMPEXP_FWD_CORE wxWindow;
 
 class WXDLLIMPEXP_CORE wxSystemThemedControlBase
@@ -24,7 +28,13 @@ public:
 protected:
     // This method is virtual and can be overridden, e.g. composite controls do
     // it to enable the system theme for all of their parts.
-    virtual void DoEnableSystemTheme(bool enable, wxWindow* window);
+    virtual void DoEnableSystemTheme
+#ifdef wxHAS_SYSTEM_THEMED_CONTROL
+    // Only __WXMSW__ has a non-trivial implementation currently.
+    (bool enable, wxWindow* window);
+#else
+    (bool WXUNUSED(enable), wxWindow* WXUNUSED(window)) { }
+#endif // wxHAS_SYSTEM_THEMED_CONTROL
 
     wxDECLARE_NO_COPY_CLASS(wxSystemThemedControlBase);
 };
@@ -47,20 +57,4 @@ protected:
     wxDECLARE_NO_COPY_TEMPLATE_CLASS(wxSystemThemedControl, C);
 };
 
-// Only __WXMSW__ has a non-trivial implementation currently.
-#if defined(__WXMSW__) && !defined(__WXUNIVERSAL__)
-    #define wxHAS_SYSTEM_THEMED_CONTROL
-#endif
-
-#ifndef wxHAS_SYSTEM_THEMED_CONTROL
-
-inline void
-wxSystemThemedControlBase::DoEnableSystemTheme(bool WXUNUSED(enable),
-                                               wxWindow* WXUNUSED(window))
-{
-    // Nothing to do.
-}
-
-#endif // !wxHAS_SYSTEM_THEMED_CONTROL
-
 #endif // _WX_SYSTHEMECTRL_H