diff --git a/src/buffer.c b/src/buffer.c
index 7a6dbc5..5a9f8a7 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -5702,8 +5702,8 @@
     signlist_T	*next;
 
     /* When deleting the last sign need to redraw the windows to remove the
-     * sign column. */
-    if (buf->b_signlist != NULL)
+     * sign column. Not when curwin is NULL (this means we're exiting). */
+    if (buf->b_signlist != NULL && curwin != NULL)
     {
 	redraw_buf_later(buf, NOT_VALID);
 	changed_cline_bef_curs();