diff --git a/src/proto/evalvars.pro b/src/proto/evalvars.pro
index c53c115..e415932 100644
--- a/src/proto/evalvars.pro
+++ b/src/proto/evalvars.pro
@@ -21,6 +21,7 @@
 void list_hashtable_vars(hashtab_T *ht, char *prefix, int empty, int *first);
 void ex_unlet(exarg_T *eap);
 void ex_lockvar(exarg_T *eap);
+void ex_unletlock(exarg_T *eap, char_u *argstart, int deep, int glv_flags, int (*callback)(lval_T *, char_u *, exarg_T *, int, void *), void *cookie);
 int do_unlet(char_u *name, int forceit);
 void del_menutrans_vars(void);
 char_u *get_user_var_name(expand_T *xp, int idx);