diff --git a/src/proto/window.pro b/src/proto/window.pro
index 0a74489..a77da59 100644
--- a/src/proto/window.pro
+++ b/src/proto/window.pro
@@ -74,4 +74,5 @@
 int match_delete __ARGS((win_T *wp, int id, int perr));
 void clear_matches __ARGS((win_T *wp));
 matchitem_T *get_match __ARGS((win_T *wp, int id));
+int get_win_number __ARGS((win_T *wp));
 /* vim: set ft=c : */