diff --git a/pyproject.toml b/pyproject.toml
index b4cc603..1525a53 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,9 +35,10 @@ requires-python = ">=3.8"
 dependencies = [
     "numpy",
     "dask",
+    "spatial_image>=0.2.1",
     "xarray",
     "xarray-datatree>=0.0.5",
-    "spatial_image>=0.2.1",
+    "zarr",
 ]
 
 [project.urls]
@@ -57,7 +58,6 @@ test = [
     "ipfsspec",
     "urllib3",
     "nbmake",
-    "zarr",
 ]
 
 itk = [