diff --git a/src/window.c b/src/window.c
index 0f4363b..be010dc 100644
--- a/src/window.c
+++ b/src/window.c
@@ -5013,6 +5013,7 @@
  * Go to another window.
  * When jumping to another buffer, stop Visual mode.  Do this before
  * changing windows so we can yank the selection into the '*' register.
+ * (note: this may trigger ModeChanged autocommand!)
  * When jumping to another window on the same buffer, adjust its cursor
  * position to keep the same Visual area.
  */
@@ -5039,10 +5040,15 @@
     }
 
     if (wp->w_buffer != curbuf)
+	// careful: triggers ModeChanged autocommand
 	reset_VIsual_and_resel();
     else if (VIsual_active)
 	wp->w_cursor = curwin->w_cursor;
 
+    // autocommand may have made wp invalid
+    if (!win_valid(wp))
+	return;
+
 #ifdef FEAT_GUI
     need_mouse_correct = TRUE;
 #endif