diff --git a/src/proto/spell.pro b/src/proto/spell.pro
index 5f91f42..e56eb92 100644
--- a/src/proto/spell.pro
+++ b/src/proto/spell.pro
@@ -3,5 +3,6 @@
 int spell_move_to __ARGS((int dir, int allwords));
 char_u *did_set_spelllang __ARGS((buf_T *buf));
 void spell_reload __ARGS((void));
+void put_bytes __ARGS((FILE *fd, long_u nr, int len));
 void ex_mkspell __ARGS((exarg_T *eap));
 /* vim: set ft=c : */