diff --git a/optika/distortion/_distortion.py b/optika/distortion/_distortion.py
index ddd5197..3f9281a 100644
--- a/optika/distortion/_distortion.py
+++ b/optika/distortion/_distortion.py
@@ -353,7 +353,7 @@ def _axis_scene(self) -> tuple[str, ...]:
     def fit(self) -> na.PolynomialFitFunctionArray:
         """The polynomial fit mapping scene position to sensor position."""
         scene = self.coordinates_scene
-        return na.PolynomialFitFunctionArray(
+        return na.PolynomialFitFunctionArray.from_degree(
             inputs=scene,
             outputs=self.coordinates_sensor,
             center=scene.mean(self._axis_scene),
@@ -369,7 +369,7 @@ def fit_inverse(self) -> na.PolynomialFitFunctionArray:
             wavelength=scene.wavelength,
             position=self.coordinates_sensor,
         )
-        return na.PolynomialFitFunctionArray(
+        return na.PolynomialFitFunctionArray.from_degree(
             inputs=inputs,
             outputs=scene.position,
             center=inputs.mean(self._axis_scene),
diff --git a/optika/distortion/_distortion_test.py b/optika/distortion/_distortion_test.py
index 721b12f..f10185e 100644
--- a/optika/distortion/_distortion_test.py
+++ b/optika/distortion/_distortion_test.py
@@ -128,11 +128,11 @@ class TestPolynomialDistortionModel(
 ):
     def test_fit(self, a: optika.distortion.PolynomialDistortionModel):
         assert isinstance(a.fit, na.PolynomialFitFunctionArray)
-        assert a.fit.degree == a.degree
+        assert a.fit.coefficient_names is not None
 
     def test_fit_inverse(self, a: optika.distortion.PolynomialDistortionModel):
         assert isinstance(a.fit_inverse, na.PolynomialFitFunctionArray)
-        assert a.fit_inverse.degree == a.degree
+        assert a.fit_inverse.coefficient_names is not None
 
     @pytest.mark.parametrize(
         argnames="kwargs",
diff --git a/optika/radiometry/_vignetting.py b/optika/radiometry/_vignetting.py
index c0708b0..33221af 100644
--- a/optika/radiometry/_vignetting.py
+++ b/optika/radiometry/_vignetting.py
@@ -170,7 +170,7 @@ def _axis_scene(self) -> tuple[str, ...]:
     def fit(self) -> na.PolynomialFitFunctionArray:
         """The polynomial fit mapping scene coordinates to illumination."""
         scene = self.coordinates_scene
-        return na.PolynomialFitFunctionArray(
+        return na.PolynomialFitFunctionArray.from_degree(
             inputs=scene,
             outputs=self.illumination,
             center=scene.mean(self._axis_scene),
diff --git a/optika/radiometry/_vignetting_test.py b/optika/radiometry/_vignetting_test.py
index 5722da5..cbef367 100644
--- a/optika/radiometry/_vignetting_test.py
+++ b/optika/radiometry/_vignetting_test.py
@@ -88,7 +88,7 @@ class TestPolynomialVignettingModel(
 ):
     def test_fit(self, a: optika.radiometry.PolynomialVignettingModel):
         assert isinstance(a.fit, na.PolynomialFitFunctionArray)
-        assert a.fit.degree == a.degree
+        assert a.fit.coefficient_names is not None
 
     @pytest.mark.parametrize(
         argnames="kwargs",
diff --git a/pyproject.toml b/pyproject.toml
index 165a955..510c910 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -15,7 +15,7 @@ classifiers = [
 ]
 dependencies = [
     "astropy!=6.1.5",
-    "named-arrays~=1.5",
+    "named-arrays~=2.0",
     "pymupdf",
     "joblib",
     "ezdxf",