diff --git a/src/proto/syntax.pro b/src/proto/syntax.pro
index 64235b0..aae187f 100644
--- a/src/proto/syntax.pro
+++ b/src/proto/syntax.pro
@@ -52,5 +52,6 @@
 int highlight_changed(void);
 void set_context_in_highlight_cmd(expand_T *xp, char_u *arg);
 char_u *get_highlight_name(expand_T *xp, int idx);
+char_u *get_highlight_name_ext(expand_T *xp, int idx, int skip_cleared);
 void free_highlight_fonts(void);
 /* vim: set ft=c : */