diff --git a/src/proto/ex_cmds.pro b/src/proto/ex_cmds.pro
index ff868ca..1669d79 100644
--- a/src/proto/ex_cmds.pro
+++ b/src/proto/ex_cmds.pro
@@ -23,6 +23,7 @@
 void ex_update __ARGS((exarg_T *eap));
 void ex_write __ARGS((exarg_T *eap));
 int do_write __ARGS((exarg_T *eap));
+int check_overwrite __ARGS((exarg_T *eap, buf_T *buf, char_u *fname, char_u *ffname, int other));
 void ex_wnext __ARGS((exarg_T *eap));
 void do_wqall __ARGS((exarg_T *eap));
 int not_writing __ARGS((void));