+#ifdef USE_PTHREADS
+extern NCURSES_EXPORT(SCREEN *) _nc_find_prescr(void);
+extern NCURSES_EXPORT(void) _nc_forget_prescr(void);
+#else
+#define _nc_find_prescr() _nc_prescreen.allocated
+#define _nc_forget_prescr() _nc_prescreen.allocated = 0
+#endif
+