diff --git a/src/keyboard.c b/src/keyboard.c
index 811ec252ef9..dc2f78a7c26 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -5942,7 +5942,7 @@ save_line_number_display_width (struct input_event *event)
   else if (FRAMEP (event->frame_or_window))
     w = XWINDOW (XFRAME (event->frame_or_window)->selected_window);
   else
-    emacs_abort ();
+    w = XWINDOW (selected_window);
   line_number_display_width (w, &down_mouse_line_number_width, &pixel_width);
 }