diff --git a/TODO b/TODO
index 3c92f565ebdbaf9f5a2f62421916566a4ab8a174..bb4a350849ce7adc8cd0be0274d48920c61881f9 100644
--- a/TODO
+++ b/TODO
@@ -79,3 +79,7 @@ Roughly in order of importance.                                     -*-org-*-
 
 * Adopt mincut/maxflow algorithm from networkx or python-graph to find the best
   representation of a lead unit cell.
+
+* Make shape a callable that uses system symmetry.
+  Similarly to HoppingKind, which requires information about sites in the
+  builder to generate hoppings, shape can be made symmetry-aware.