diff --git a/src/proto/charset.pro b/src/proto/charset.pro
index fc7769c..dd3b6f2 100644
--- a/src/proto/charset.pro
+++ b/src/proto/charset.pro
@@ -49,7 +49,7 @@
 char_u *skiptowhite_esc __ARGS((char_u *p));
 long getdigits __ARGS((char_u **pp));
 int vim_isblankline __ARGS((char_u *lbuf));
-void vim_str2nr __ARGS((char_u *start, int *hexp, int *len, int dooct, int dohex, long *nptr, unsigned long *unptr));
+void vim_str2nr __ARGS((char_u *start, int *hexp, int *len, int dooct, int dohex, long *nptr, unsigned long *unptr, int strlen));
 int hex2nr __ARGS((int c));
 int hexhex2nr __ARGS((char_u *p));
 int rem_backslash __ARGS((char_u *str));