diff --git a/src/proto/vim9script.pro b/src/proto/vim9script.pro
index 41bf128..14f0800 100644
--- a/src/proto/vim9script.pro
+++ b/src/proto/vim9script.pro
@@ -16,7 +16,7 @@
 void update_vim9_script_var(int create, dictitem_T *di, int flags, typval_T *tv, type_T **type, int do_member);
 void hide_script_var(scriptitem_T *si, int idx, int func_defined);
 void free_all_script_vars(scriptitem_T *si);
-svar_T *find_typval_in_script(typval_T *dest);
+svar_T *find_typval_in_script(typval_T *dest, int give_error);
 int check_script_var_type(typval_T *dest, typval_T *value, char_u *name, where_T where);
 int check_reserved_name(char_u *name);
 /* vim: set ft=c : */