diff --git a/src/waveresponse/_core.py b/src/waveresponse/_core.py
index 8a526cc..4f89d4c 100644
--- a/src/waveresponse/_core.py
+++ b/src/waveresponse/_core.py
@@ -598,7 +598,7 @@ def rotate(self, angle, degrees=False):
         dirs_new = _robust_modulus(new._dirs - angle, 2.0 * np.pi)
         new._dirs, new._vals = _sort(dirs_new, new._vals)
         return new
-    
+
     def _interpolate_function(self, complex_convert="rectangular", **kw):
         """
         Interpolation function based on ``scipy.interpolate.interp2d``.
@@ -606,7 +606,7 @@ def _interpolate_function(self, complex_convert="rectangular", **kw):
         xp = np.concatenate(
             (self._dirs[-1:] - 2 * np.pi, self._dirs, self._dirs[:1] + 2.0 * np.pi)
         )
-        
+
         yp = self._freq
         zp = np.concatenate(
             (
@@ -616,7 +616,7 @@ def _interpolate_function(self, complex_convert="rectangular", **kw):
             ),
             axis=1,
         )
-        
+
         if np.all(np.isreal(zp)):
             return RGI((xp, yp), zp.T, **kw)
         elif complex_convert.lower() == "polar":
@@ -648,7 +648,6 @@ def interpolate(
         complex_convert="rectangular",
         fill_value=0.0,
     ):
-        
         freq = np.asarray_chkfinite(freq).reshape(-1)
         dirs = np.asarray_chkfinite(dirs).reshape(-1)
 
@@ -662,11 +661,14 @@ def interpolate(
         self._check_dirs(dirs)
 
         interp_fun = self._interpolate_function(
-            complex_convert=complex_convert, method='linear', bounds_error=False, fill_value = fill_value
+            complex_convert=complex_convert,
+            method="linear",
+            bounds_error=False,
+            fill_value=fill_value,
         )
-        xxnew, yynew = np.meshgrid(dirs, freq, indexing='ij', sparse=True)
+        xxnew, yynew = np.meshgrid(dirs, freq, indexing="ij", sparse=True)
         return interp_fun((xxnew, yynew)).T
-    
+
     def reshape(
         self,
         freq,
diff --git a/src/waveresponse/_standardized1d.py b/src/waveresponse/_standardized1d.py
index 55a0dcf..6063617 100644
--- a/src/waveresponse/_standardized1d.py
+++ b/src/waveresponse/_standardized1d.py
@@ -556,7 +556,9 @@ def _spectrum(self, omega, hs, tp):
         A_secondary = (3.26 / 16.0) * hs_secondary**2 * omega_p_secondary**3
         B_secondary = omega_p_secondary**4
 
-        spectrum_secondary = A_secondary / omega**4 * np.exp(-B_secondary / omega**4)
+        spectrum_secondary = (
+            A_secondary / omega**4 * np.exp(-B_secondary / omega**4)
+        )
 
         return spectrum_primary + spectrum_secondary
 
diff --git a/tests/test_core.py b/tests/test_core.py
index 7deff64..a7a2d59 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -1367,7 +1367,7 @@ def test_interpolate(self):
         vals_expect = np.array([[a * x_i + b * y_i for x_i in x] for y_i in y])
 
         vals_out = grid.interpolate(y, x, freq_hz=True, degrees=True)
-      
+
         np.testing.assert_array_almost_equal(vals_out, vals_expect)
 
     def test_interpolate2(self):
@@ -3360,7 +3360,9 @@ def test_moment_m2_rads(self):
 
         m_out = spectrum.moment(2, freq_hz=False)
 
-        m_expect = (1.0 / 3.0) * (0.0 - 360.0) * (f0**3 - f1**3) * (2.0 * np.pi) ** 2
+        m_expect = (
+            (1.0 / 3.0) * (0.0 - 360.0) * (f0**3 - f1**3) * (2.0 * np.pi) ** 2
+        )
 
         # not exactly same due to error in trapezoid for higher order functions
         assert m_out == pytest.approx(m_expect, rel=0.1)