diff --git a/src/window.c b/src/window.c
index e801ff821f..d06a706e58 100644
--- a/src/window.c
+++ b/src/window.c
@@ -6307,10 +6307,12 @@ DEFUN ("other-window-for-scrolling", Fother_window_for_scrolling, Sother_window_
       if (NILP (window))
 	window = display_buffer (Vother_window_scroll_buffer, Qt, Qnil);
     }
+  else if (FUNCTIONP (Vother_window_scroll_default))
+    /* Nothing specified; try to get a window from the function.  */
+    window = call0 (Vother_window_scroll_default);
   else
     {
-      /* Nothing specified; look for a neighboring window on the same
-	 frame.  */
+      /* Otherwise, look for a neighboring window on the same frame.  */
       window = Fnext_window (selected_window, Qlambda, Qnil);
 
       if (EQ (window, selected_window))
@@ -8268,6 +8270,15 @@ syms_of_window (void)
 	       doc: /* If this is a live buffer, \\[scroll-other-window] should scroll its window.  */);
   Vother_window_scroll_buffer = Qnil;
 
+  DEFVAR_LISP ("other-window-scroll-default", Vother_window_scroll_default,
+	       doc: /* Function that provides the window to scroll by \\[scroll-other-window].
+The function `other-window-for-scrolling' first tries to use
+`minibuffer-scroll-window' and `other-window-scroll-buffer'.
+But when both are nil, then by default it uses a neighboring window.
+This variable is intended to provide another default instead of
+a neighboring window.  */);
+  Vother_window_scroll_default = Qnil;
+
   DEFVAR_BOOL ("auto-window-vscroll", auto_window_vscroll_p,
 	       doc: /* Non-nil means to automatically adjust `window-vscroll' to view tall lines.  */);
   auto_window_vscroll_p = true;