diff --git a/src/proto/userfunc.pro b/src/proto/userfunc.pro
index 91d5711..7bedac0 100644
--- a/src/proto/userfunc.pro
+++ b/src/proto/userfunc.pro
@@ -1,6 +1,7 @@
 /* userfunc.c */
 void func_init(void);
 hashtab_T *func_tbl_get(void);
+char_u *make_ufunc_name_readable(char_u *name, char_u *buf, size_t bufsize);
 char_u *get_lambda_name(void);
 char_u *register_cfunc(cfunc_T cb, cfunc_free_T cb_free, void *state);
 int get_lambda_tv(char_u **arg, typval_T *rettv, int types_optional, evalarg_T *evalarg);