diff --git a/src/proto/ex_docmd.pro b/src/proto/ex_docmd.pro
index 40f2649..d67cb9a 100644
--- a/src/proto/ex_docmd.pro
+++ b/src/proto/ex_docmd.pro
@@ -63,7 +63,7 @@
 void exec_normal_cmd(char_u *cmd, int remap, int silent);
 void exec_normal(int was_typed, int use_vpeekc, int may_use_terminal_loop);
 int find_cmdline_var(char_u *src, int *usedlen);
-char_u *eval_vars(char_u *src, char_u *srcstart, int *usedlen, linenr_T *lnump, char **errormsg, int *escaped);
+char_u *eval_vars(char_u *src, char_u *srcstart, int *usedlen, linenr_T *lnump, char **errormsg, int *escaped, int empty_is_error);
 char_u *expand_sfile(char_u *arg);
 void dialog_msg(char_u *buff, char *format, char_u *fname);
 void set_no_hlsearch(int flag);