diff --git a/src/proto/buffer.pro b/src/proto/buffer.pro
index ad205c0..9e97f67 100644
--- a/src/proto/buffer.pro
+++ b/src/proto/buffer.pro
@@ -52,6 +52,7 @@
 int read_viminfo_bufferlist __ARGS((vir_T *virp, int writing));
 void write_viminfo_bufferlist __ARGS((FILE *fp));
 char_u *buf_spname __ARGS((buf_T *buf));
+int find_win_for_buf __ARGS((buf_T *buf, win_T **wp, tabpage_T **tp));
 void buf_addsign __ARGS((buf_T *buf, int id, linenr_T lnum, int typenr));
 linenr_T buf_change_sign_type __ARGS((buf_T *buf, int markId, int typenr));
 int buf_getsigntype __ARGS((buf_T *buf, linenr_T lnum, int type));