diff --git a/src/proto/ex_cmds.pro b/src/proto/ex_cmds.pro
index 315b6bb..ff868ca 100644
--- a/src/proto/ex_cmds.pro
+++ b/src/proto/ex_cmds.pro
@@ -9,7 +9,7 @@
 void do_bang __ARGS((int addr_count, exarg_T *eap, int forceit, int do_in, int do_out));
 void do_shell __ARGS((char_u *cmd, int flags));
 char_u *make_filter_cmd __ARGS((char_u *cmd, char_u *itmp, char_u *otmp));
-void append_redir __ARGS((char_u *buf, char_u *opt, char_u *fname));
+void append_redir __ARGS((char_u *buf, int buflen, char_u *opt, char_u *fname));
 int viminfo_error __ARGS((char *errnum, char *message, char_u *line));
 int read_viminfo __ARGS((char_u *file, int flags));
 void write_viminfo __ARGS((char_u *file, int forceit));