diff --git a/src/proto/buffer.pro b/src/proto/buffer.pro
index 82bcaf3..564b655 100644
--- a/src/proto/buffer.pro
+++ b/src/proto/buffer.pro
@@ -5,7 +5,7 @@
 void set_bufref(bufref_T *bufref, buf_T *buf);
 int bufref_valid(bufref_T *bufref);
 int buf_valid(buf_T *buf);
-void close_buffer(win_T *win, buf_T *buf, int action, int abort_if_last, int ignore_abort);
+int close_buffer(win_T *win, buf_T *buf, int action, int abort_if_last, int ignore_abort);
 void buf_clear_file(buf_T *buf);
 void buf_freeall(buf_T *buf, int flags);
 void free_wininfo(wininfo_T *wip);