diff --git a/packages/gtk2/src/gtk+/gtk/gtkbox.inc b/packages/gtk2/src/gtk+/gtk/gtkbox.inc
index 75ec203ba4..045aeff51e 100644
--- a/packages/gtk2/src/gtk+/gtk/gtkbox.inc
+++ b/packages/gtk2/src/gtk+/gtk/gtkbox.inc
@@ -11,7 +11,7 @@
         container : TGtkContainer;
         children : PGList;
         spacing : gint16;
-        flag0 : word;
+        flag0 : {$ifdef win32}longint{$else}word{$endif};
      end;
 
    PGtkBoxClass = ^TGtkBoxClass;