diff --git a/src/proto/option.pro b/src/proto/option.pro
index 40312f4..b3c66ee 100644
--- a/src/proto/option.pro
+++ b/src/proto/option.pro
@@ -80,6 +80,7 @@
 void find_mps_values(int *initc, int *findc, int *backwards, int switchit);
 int briopt_check(win_T *wp);
 unsigned int get_bkc_value(buf_T *buf);
+char_u *get_showbreak_value(win_T *win);
 int signcolumn_on(win_T *wp);
 dict_T *get_winbuf_options(int bufopt);
 int fill_culopt_flags(char_u *val, win_T *wp);