diff --git a/src/proto/screen.pro b/src/proto/screen.pro
index fd6a1fa..c2ce8d7 100644
--- a/src/proto/screen.pro
+++ b/src/proto/screen.pro
@@ -10,6 +10,7 @@
 void update_screen __ARGS((int type));
 void update_debug_sign __ARGS((buf_T *buf, linenr_T lnum));
 void updateWindow __ARGS((win_T *wp));
+void rl_mirror __ARGS((char_u *str));
 void status_redraw_all __ARGS((void));
 void status_redraw_curbuf __ARGS((void));
 void redraw_statuslines __ARGS((void));