diff --git a/src/pysm3/utils/spherical_harmonics.py b/src/pysm3/utils/spherical_harmonics.py
index 46b10dca..bc3ae63e 100644
--- a/src/pysm3/utils/spherical_harmonics.py
+++ b/src/pysm3/utils/spherical_harmonics.py
@@ -128,6 +128,8 @@ def apply_smoothing_and_coord_transform(
                     copy=False,
                 )
             )
+            output_maps.append(shape)
+            output_map.append(wcs)
     else:
         assert (rot is None) or (
             rot.coordin == rot.coordout