diff --git a/src/proto/map.pro b/src/proto/map.pro
index 05d66fb..cf1b31a 100644
--- a/src/proto/map.pro
+++ b/src/proto/map.pro
@@ -4,6 +4,7 @@
 int is_maphash_valid(void);
 int do_map(int maptype, char_u *arg, int mode, int abbrev);
 void map_clear_int(buf_T *buf, int mode, int local, int abbr);
+int mode_str2flags(char_u *modechars);
 int map_to_exists(char_u *str, char_u *modechars, int abbr);
 int map_to_exists_mode(char_u *rhs, int mode, int abbr);
 char_u *set_context_in_map_cmd(expand_T *xp, char_u *cmd, char_u *arg, int forceit, int isabbrev, int isunmap, cmdidx_T cmdidx);