1 files changed, 3 insertions, 1 deletions

diff --git a/src/window.h b/src/window.h
index ca507cd1625..aa4b18335ce 100644
--- a/src/window.h
+++ b/src/window.h
@@ -375,7 +375,9 @@ extern void set_window_height P_ ((Lisp_Object, int, int));
 extern void set_window_width P_ ((Lisp_Object, int, int));
 extern void delete_all_subwindows P_ ((struct window *));
 extern void freeze_window_starts P_ ((struct frame *, int));
-extern void foreach_window ();
+extern void foreach_window P_ ((struct frame *,
+                                int (* fn) (struct window *, void *),
+                                void *));
 extern void grow_mini_window P_ ((struct window *, int));
 extern void shrink_mini_window P_ ((struct window *));