diff --git a/src/proto/misc2.pro b/src/proto/misc2.pro
index 144324f..83384c0 100644
--- a/src/proto/misc2.pro
+++ b/src/proto/misc2.pro
@@ -40,6 +40,7 @@
 char_u *vim_strnsave_up(char_u *string, int len);
 void vim_strup(char_u *p);
 char_u *strup_save(char_u *orig);
+char_u *strlow_save(char_u *orig);
 void del_trailing_spaces(char_u *ptr);
 void vim_strncpy(char_u *to, char_u *from, size_t len);
 void vim_strcat(char_u *to, char_u *from, size_t tosize);