diff --git a/kwant/lattice.py b/kwant/lattice.py
index 83e938b9a195a71beaca8aa79c958564d4eba182..844815f888a0afe9a3edf0ba33599578146bea6b 100644
--- a/kwant/lattice.py
+++ b/kwant/lattice.py
@@ -660,3 +660,7 @@ def kagome(a=1, name=''):
     lat = Polyatomic(a * tri, ((0, 0),) + tuple(0.5 * a * tri), name=name)
     lat.a, lat.b, lat.c = lat.sublattices
     return lat
+
+
+# TODO (Anton): unhide _prim_vecs, once tinyarray supports indexing of
+# sub-arrays.