diff --git a/pyproject.toml b/pyproject.toml
index 9ad5b3b..239cc1e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,10 +33,10 @@ dependencies = [
 legacy = ["imagecodecs"]
 tiff = ["tifffile"]
 test = [
-    "nd2[legacy]",
     "nd2[tiff]",
-    "aicsimageio",
+    "aicsimageio; python_version <= '3.12'",
     "dask[array]",
+    "imagecodecs; python_version <= '3.12'",
     "lxml; python_version >= '3.9' and python_version <= '3.12'",
     "numpy",
     "psutil",
diff --git a/src/nd2/tiff.py b/src/nd2/tiff.py
index 8ddf394..313b4f7 100644
--- a/src/nd2/tiff.py
+++ b/src/nd2/tiff.py
@@ -184,7 +184,7 @@ def position_iter(p: int) -> Iterator[np.ndarray]:
                     shape=shape,
                     dtype=nd2f.dtype,
                     resolution=(1 / pixelsize, 1 / pixelsize),
-                    resolutionunit=tf.TIFF.RESUNIT.MICROMETER,
+                    resolutionunit=tf.RESUNIT.MICROMETER,
                     photometric=photometric,
                     metadata=metadata,
                     description=ome_xml,