diff --git a/meshmode/mesh/__init__.py b/meshmode/mesh/__init__.py
index 3bbf2c2c8804d3acb05897e9f7f7e46c6fe68daa..d0f6df3b9a3e6092e527670c49fd9ec9d8057e44 100644
--- a/meshmode/mesh/__init__.py
+++ b/meshmode/mesh/__init__.py
@@ -1396,6 +1396,7 @@ def is_affine_simplex_group(group, abs_tol=None):
     if norm_inf > abs_tol:
         return False
 
+    # check all elements for a non-affine local-to-global mapping
     ddx_coeffs = np.einsum("aij,bcj->abci", mats, group.nodes)
     norm_inf = np.max(np.abs(ddx_coeffs))
     return norm_inf < abs_tol