diff --git a/boule/_ellipsoid.py b/boule/_ellipsoid.py
index 1b4912bb..6568d029 100644
--- a/boule/_ellipsoid.py
+++ b/boule/_ellipsoid.py
@@ -668,9 +668,7 @@ def geodetic_to_ellipsoidal_harmonic(self, longitude, latitude, height):
 
         # Reduced latitude of the projection of the point on the
         # reference ellipsoid
-        beta = np.arctan2(
-            self.semiminor_axis * sinlat, self.semimajor_axis * coslat
-        )
+        beta = np.arctan2(self.semiminor_axis * sinlat, self.semimajor_axis * coslat)
         sinbeta = np.sin(beta)
         cosbeta = np.sqrt(1 - sinbeta**2)