diff --git a/changes/441.feature.rst b/changes/441.feature.rst
index 28c11b8d..fd37413b 100644
--- a/changes/441.feature.rst
+++ b/changes/441.feature.rst
@@ -1 +1 @@
-Added support for skycell reference file
\ No newline at end of file
+Added support for skycell reference file
diff --git a/src/roman_datamodels/maker_utils/_common_meta.py b/src/roman_datamodels/maker_utils/_common_meta.py
index 6eb2da2a..55aa4395 100644
--- a/src/roman_datamodels/maker_utils/_common_meta.py
+++ b/src/roman_datamodels/maker_utils/_common_meta.py
@@ -753,6 +753,7 @@ def mk_ref_readnoise_meta(**kwargs):
 
     return meta
 
+
 def mk_ref_skycells_meta(**kwargs):
     """
     Create dummy metadata for skycells reference file instances.
@@ -770,6 +771,7 @@ def mk_ref_skycells_meta(**kwargs):
 
     return meta
 
+
 def mk_mosaic_basic(**kwargs):
     """
     Create a dummy mosaic basic instance with valid values for attributes
diff --git a/src/roman_datamodels/maker_utils/_ref_files.py b/src/roman_datamodels/maker_utils/_ref_files.py
index d23a49a3..ee528b62 100644
--- a/src/roman_datamodels/maker_utils/_ref_files.py
+++ b/src/roman_datamodels/maker_utils/_ref_files.py
@@ -14,8 +14,8 @@
     mk_ref_epsf_meta,
     mk_ref_pixelarea_meta,
     mk_ref_readnoise_meta,
-    mk_ref_units_dn_meta,
     mk_ref_skycells_meta,
+    mk_ref_units_dn_meta,
 )
 
 __all__ = [
@@ -33,10 +33,10 @@
     "mk_pixelarea",
     "mk_readnoise",
     "mk_refpix",
+    "mk_roman_skycells",
     "mk_saturation",
     "mk_superbias",
     "mk_wfi_img_photom",
-    "mk_roman_skycells",
 ]
 
 OPT_ELEM = ("F062", "F087", "F106", "F129", "F146", "F158", "F184", "F213", "GRISM", "PRISM", "DARK")
@@ -566,61 +566,170 @@ def mk_saturation(*, shape=(4096, 4096), filepath=None, **kwargs):
 
     return save_node(saturationref, filepath=filepath)
 
+
 def mk_roman_skycells(*, filepath=None, **kwargs):
     skycellref = stnode.RomanSkycellsRef()
     skycellref["meta"] = mk_ref_skycells_meta(**kwargs)
-    proj_dtype = np.dtype([('index', '<i4'),
-                           ('ra_tangent', '<f8'),
-                           ('dec_tangent', '<f8'),
-                           ('ra_min', '<f8'),
-                           ('ra_max', '<f8'),
-                           ('dec_min', '<f8'),
-                           ('dec_max', '<f8'),
-                           ('orientat', '<f4'),
-                           ('x_tangent', '<f8'),
-                           ('y_tangent', '<f8'),
-                           ('nx', '<i4'),
-                           ('ny', '<i4'),
-                           ('skycell_start', '<i4'),
-                           ('skycell_end', '<i4'),
-                           ('nxy_skycell', '<i4'),
-                           ('skycell_border_pixels', '<i4'),
-                           ('pixel_scale', '<f4')])
-    skycell_dtype = np.dtype([('name', '<U16'),
-                              ('ra_center', '<f8'),
-                              ('dec_center', '<f8'),
-                              ('orientat', '<f4'),
-                              ('x_tangent', '<f8'),
-                              ('y_tangent', '<f8'),
-                              ('ra_corn1', '<f8'),
-                              ('dec_corn1', '<f8'),
-                              ('ra_corn2', '<f8'),
-                              ('dec_corn2', '<f8'),
-                              ('ra_corn3', '<f8'),
-                              ('dec_corn3', '<f8'),
-                              ('ra_corn4', '<f8'),
-                              ('dec_corn4', '<f8')])
+    proj_dtype = np.dtype(
+        [
+            ("index", "<i4"),
+            ("ra_tangent", "<f8"),
+            ("dec_tangent", "<f8"),
+            ("ra_min", "<f8"),
+            ("ra_max", "<f8"),
+            ("dec_min", "<f8"),
+            ("dec_max", "<f8"),
+            ("orientat", "<f4"),
+            ("x_tangent", "<f8"),
+            ("y_tangent", "<f8"),
+            ("nx", "<i4"),
+            ("ny", "<i4"),
+            ("skycell_start", "<i4"),
+            ("skycell_end", "<i4"),
+            ("nxy_skycell", "<i4"),
+            ("skycell_border_pixels", "<i4"),
+            ("pixel_scale", "<f4"),
+        ]
+    )
+    skycell_dtype = np.dtype(
+        [
+            ("name", "<U16"),
+            ("ra_center", "<f8"),
+            ("dec_center", "<f8"),
+            ("orientat", "<f4"),
+            ("x_tangent", "<f8"),
+            ("y_tangent", "<f8"),
+            ("ra_corn1", "<f8"),
+            ("dec_corn1", "<f8"),
+            ("ra_corn2", "<f8"),
+            ("dec_corn2", "<f8"),
+            ("ra_corn3", "<f8"),
+            ("dec_corn3", "<f8"),
+            ("ra_corn4", "<f8"),
+            ("dec_corn4", "<f8"),
+        ]
+    )
     proj_tab = np.array(
-        [(   0, 225.,  90.        ,   0. , 360. ,  88.20062575,  90.        , 0.,
-            117776.5, 117776.5, 235554, 235554,       0,    1985, 5000, 100, 1.5277777e-05),
-         (   1,   0.,  86.40080763, -22.5,  22.5,  84.60010081,  88.20062575, 0.,
-            138592.5, 117834.5, 277186, 235670,    1985,    3986, 5000, 100, 1.5277777e-05),
-         (   2,  45.,  86.40080763,  22.5,  67.5,  84.60010081,  88.20062575, 0.,
-            138592.5, 117834.5, 277186, 235670,    3986,    5987, 5000, 100, 1.5277777e-05),
-         ], dtype=proj_dtype)
+        [
+            (
+                0,
+                225.0,
+                90.0,
+                0.0,
+                360.0,
+                88.20062575,
+                90.0,
+                0.0,
+                117776.5,
+                117776.5,
+                235554,
+                235554,
+                0,
+                1985,
+                5000,
+                100,
+                1.5277777e-05,
+            ),
+            (
+                1,
+                0.0,
+                86.40080763,
+                -22.5,
+                22.5,
+                84.60010081,
+                88.20062575,
+                0.0,
+                138592.5,
+                117834.5,
+                277186,
+                235670,
+                1985,
+                3986,
+                5000,
+                100,
+                1.5277777e-05,
+            ),
+            (
+                2,
+                45.0,
+                86.40080763,
+                22.5,
+                67.5,
+                84.60010081,
+                88.20062575,
+                0.0,
+                138592.5,
+                117834.5,
+                277186,
+                235670,
+                3986,
+                5987,
+                5000,
+                100,
+                1.5277777e-05,
+            ),
+        ],
+        dtype=proj_dtype,
+    )
     skycell_tab = np.array(
-        [('a225dp90xm25yp01', 317.2901524 ,  88.16584325, -92.29015 ,  122499.5,  7299.5, 318.40988935,  88.12583697,
-           318.55462778,  88.20200659, 316.1209133 ,  88.20512017, 316.07517233,  88.12882346),
-         ('a225dp90xm25yp00', 314.99952253,  88.16730723, -89.99952 ,  122499.5,  2499.5, 316.16868134,  88.1287637,
-            316.2183982 ,  88.20505786, 313.78062699,  88.20505721, 313.8303836 ,  88.12876307),
-         ('a225dp90xm25yp01', 312.70889418,  88.16584203, -87.70889 ,  122499.5, -2300.5, 313.92389255,  88.12882289,
-            313.87811182,  88.20511958, 311.44440071,  88.2020047 , 311.58917851,  88.12583515),
-         ], dtype=skycell_dtype)
+        [
+            (
+                "a225dp90xm25yp01",
+                317.2901524,
+                88.16584325,
+                -92.29015,
+                122499.5,
+                7299.5,
+                318.40988935,
+                88.12583697,
+                318.55462778,
+                88.20200659,
+                316.1209133,
+                88.20512017,
+                316.07517233,
+                88.12882346,
+            ),
+            (
+                "a225dp90xm25yp00",
+                314.99952253,
+                88.16730723,
+                -89.99952,
+                122499.5,
+                2499.5,
+                316.16868134,
+                88.1287637,
+                316.2183982,
+                88.20505786,
+                313.78062699,
+                88.20505721,
+                313.8303836,
+                88.12876307,
+            ),
+            (
+                "a225dp90xm25yp01",
+                312.70889418,
+                88.16584203,
+                -87.70889,
+                122499.5,
+                -2300.5,
+                313.92389255,
+                88.12882289,
+                313.87811182,
+                88.20511958,
+                311.44440071,
+                88.2020047,
+                311.58917851,
+                88.12583515,
+            ),
+        ],
+        dtype=skycell_dtype,
+    )
     skycellref["projection_regions"] = proj_tab
     skycellref["skycells"] = skycell_tab
 
     return save_node(skycellref, filepath=filepath)
 
+
 def mk_superbias(*, shape=(4096, 4096), filepath=None, **kwargs):
     """
     Create a dummy Superbias instance (or file) with arrays and valid values for
diff --git a/src/roman_datamodels/maker_utils/mk_skycell_ref.py b/src/roman_datamodels/maker_utils/mk_skycell_ref.py
index c7efe684..2bf5c3bb 100644
--- a/src/roman_datamodels/maker_utils/mk_skycell_ref.py
+++ b/src/roman_datamodels/maker_utils/mk_skycell_ref.py
@@ -1,15 +1,11 @@
+import asdf
 import numpy as np
 from astropy.time import Time
-import asdf
+
 import roman_datamodels.stnode as stnode
 
-def mk_skycell(output_filename,
-               projection_regions,
-               skycells,
-               author,
-               useafter,
-               plate_scale,
-               border_pixels):
+
+def mk_skycell(output_filename, projection_regions, skycells, author, useafter, plate_scale, border_pixels):
     """
     Create a skycell reference file.
 
@@ -41,9 +37,7 @@ def mk_skycell(output_filename,
         "useafter": Time("2024-01-01T01:00:00.000"),
         "telescope": "ROMAN",
         "origin": "STSCI",
-        "instrument": {
-            "name": "WFI"
-        },
+        "instrument": {"name": "WFI"},
         "nxy_skycell": 5000,
         "skycell_border_pixels": border_pixels,
         "plate_scale": plate_scale,
@@ -51,11 +45,11 @@ def mk_skycell(output_filename,
     projection_regions = np.array(projection_regions)
     skycells = np.array(skycells)
     skycellref = stnode.RomanSkycellsRef()
-    skycellref['meta'] = meta
-    skycellref['projection_regions'] = projection_regions
-    skycellref['skycells'] = skycells
-    skycellref['datamodel_name'] = "RomanSkycellsRefModel"
+    skycellref["meta"] = meta
+    skycellref["projection_regions"] = projection_regions
+    skycellref["skycells"] = skycells
+    skycellref["datamodel_name"] = "RomanSkycellsRefModel"
     with asdf.AsdfFile() as afout:
         afout = asdf.AsdfFile()
-        afout.tree['roman'] = skycellref
+        afout.tree["roman"] = skycellref
         afout.write_to(output_filename)
diff --git a/tests/test_maker_utils.py b/tests/test_maker_utils.py
index b682a942..caf40b00 100644
--- a/tests/test_maker_utils.py
+++ b/tests/test_maker_utils.py
@@ -147,6 +147,7 @@ def test_override_data(node_class):
     # Skip the test if it is a RomanSkycellsRef class
     if node_class.__name__ == "RomanSkycellsRef":
         return
+
     def mutate_value(value):
         """
         Generate a mutated value for a given value.
diff --git a/tests/test_models.py b/tests/test_models.py
index bba75273..4e3abd2a 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -329,7 +329,7 @@ def test_reference_file_model_base(tmp_path):
     tags = [t for t in stnode.NODE_EXTENSIONS[0].tags if "/reference_files/" in t.tag_uri]
     for tag in tags:
         # roman_skycells doesn't use EXPECTED_COMMON_REFERENCE
-        if repr(tag).find('roman_skycells') > 0:
+        if repr(tag).find("roman_skycells") > 0:
             return
         schema = asdf.schema.load_schema(tag.schema_uris[0])
         # Check that schema references common reference schema
@@ -614,11 +614,13 @@ def test_make_refpix():
     assert refpix.meta.input_units == u.DN
     assert refpix.meta.output_units == u.DN
 
+
 # Skycells tests
 def test_make_roman_skycells():
     skycells_ref = utils.mk_roman_skycells()
     assert skycells_ref.projection_regions["index"][2] == 2
-    assert skycells_ref.skycells['dec_corn2'][0] > 88
+    assert skycells_ref.skycells["dec_corn2"][0] > 88
+
 
 # WFI Photom tests
 def test_make_wfi_img_photom():