diff --git a/include/wx/univ/window.h b/include/wx/univ/window.h
index d13c7657a6..0190f10616 100644
--- a/include/wx/univ/window.h
+++ b/include/wx/univ/window.h
@@ -254,8 +254,13 @@ protected:
     bool m_isCurrent:1;
 
 #ifdef __WXMSW__
+
+#if wxABI_VERSION >= 20602
+public:
+#endif
     // override MSWWindowProc() to process WM_NCHITTEST
     WXLRESULT MSWWindowProc(WXUINT message, WXWPARAM wParam, WXLPARAM lParam);
+
 #endif // __WXMSW__
 
 private:
diff --git a/version-script.in b/version-script.in
index 1f378028ce..36ef28913f 100644
--- a/version-script.in
+++ b/version-script.in
@@ -24,6 +24,7 @@
         *wxMessageOutputBest*;
         *wxShadowObject*;
         *wxTopLevelWindowGTK*RequestUserAttention*;
+        *wxWindowMSW*MSWWindowProc*;
         *wxWizard*FinishLayout*;
         *wxWizardPage*TransferDataFromWindow*;
         *wxWizardPage*TransferDataToWindow*;