diff --git a/pyproject.toml b/pyproject.toml
index 03465d3..e7218bf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,7 @@ requires = [
   "wheel",
   "imagecodecs>=2021.2.26",
   "numpy",
-  "ome-types>=0.6.2",
+  "ome-types>=0.4.2",
   "zarr>=2.6.1,<3",
   "scyjava",
   "jpype1",
@@ -22,7 +22,7 @@ dynamic = ["version"]
 dependencies = [
     "imagecodecs>=2021.2.26",
     "numpy",
-    "ome-types>=0.6.2",
+    "ome-types>=0.4.2",
     "zarr>=2.6.1,<3",
     "scyjava",
     "jpype1",
diff --git a/src/bfio/utils.py b/src/bfio/utils.py
index 2330f44..f0df213 100644
--- a/src/bfio/utils.py
+++ b/src/bfio/utils.py
@@ -418,7 +418,7 @@ def pixels_per_cm(
         UnitsLength.YOCTOMETER: 1e-22,  # 1 yoctometer = 1e-22 centimeters
         # SI-derived Units
         # 1 ångström = 1e-8 centimeters
-        UnitsLength.LATIN_CAPITAL_LETTER_A_WITH_RING_ABOVE: 1e-8,
+        UnitsLength.ANGSTROM: 1e-8,
         # Imperial Units
         UnitsLength.THOU: 2.54e-3,  # 1 thou (mil) = 0.001 inch = 2.54e-3 centimeters
         UnitsLength.LINE: 2.11667,  # 1 line = 1/12 inch = 2.11667 centimeters