diff --git a/src/main.c b/src/main.c
index 895a435..c79d2b8 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1198,7 +1198,9 @@
 			|| conceal_cursor_line(curwin)
 			|| need_cursor_line_redraw))
 	    {
-		if (conceal_old_cursor_line != conceal_new_cursor_line)
+		if (conceal_old_cursor_line != conceal_new_cursor_line
+			&& conceal_old_cursor_line
+						<= curbuf->b_ml.ml_line_count)
 		    update_single_line(curwin, conceal_old_cursor_line);
 		update_single_line(curwin, conceal_new_cursor_line);
 		curwin->w_valid &= ~VALID_CROW;