diff -r 06e03c7e39db -r be4c88ded783 ui/win32/button.h
--- a/ui/win32/button.h	Wed Nov 26 19:39:37 2025 +0100
+++ b/ui/win32/button.h	Thu Nov 27 15:15:09 2025 +0100
@@ -34,14 +34,14 @@
 
 W32Size ui_button_get_preferred_size(W32Widget *widget);
 
-void ui_button_eventproc(W32Widget *widget, HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
+int ui_button_eventproc(W32Widget *widget, HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
 
 int64_t ui_togglebutton_get(UiInteger *i);
 void ui_togglebutton_set(UiInteger *i, int64_t v);
-void ui_togglebutton_eventproc(W32Widget *widget, HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
+int ui_togglebutton_eventproc(W32Widget *widget, HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
 
 int64_t ui_radiobutton_get(UiInteger *i);
 void ui_radiobutton_set(UiInteger *i, int64_t v);
-void ui_radiobutton_eventproc(W32Widget *widget, HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
+int ui_radiobutton_eventproc(W32Widget *widget, HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
 
 #endif //BUTTON_H