diff --git a/iohub/ngff.py b/iohub/ngff.py
index ac3d91e2..19b9d29a 100644
--- a/iohub/ngff.py
+++ b/iohub/ngff.py
@@ -929,7 +929,7 @@ def initialize_pyramid(self, levels: int) -> None:
             )
 
             chunks = _pad_shape(
-                _scale_integers(array.shape[-3:], factor), len(shape)
+                _scale_integers(array.chunks, factor), len(shape)
             )
 
             transforms = deepcopy(