diff --git a/th01/hardware/ztext.h b/th01/hardware/ztext.h
index 255b0a05..7a8218d7 100644
--- a/th01/hardware/ztext.h
+++ b/th01/hardware/ztext.h
@@ -18,4 +18,5 @@ void z_text_show(void);
 void z_text_hide(void);
 void z_text_setcursor(z_text_cursor_t type);
 void z_text_print(const char *cmd);
+void z_text_vputsa(tram_x_t x, tram_y_t y, int z_atrb, const char *fmt, ...);
 // ------------------------------------------