diff --git a/improver_tests/utilities/spatial/test_DistanceBetweenGridSquares.py b/improver_tests/utilities/spatial/test_DistanceBetweenGridSquares.py
index 368fe0464b..6c867185a3 100644
--- a/improver_tests/utilities/spatial/test_DistanceBetweenGridSquares.py
+++ b/improver_tests/utilities/spatial/test_DistanceBetweenGridSquares.py
@@ -5,18 +5,17 @@
 """ Tests of DifferenceBetweenAdjacentGridSquares plugin, which encompasses all paths through
 LatLonCubeDistanceCalculator, ProjectionCubeDistanceCalculator and BaseDistanceCalculator."""
 from typing import Tuple
-import pytest
 
 import numpy as np
-from iris.cube import Cube
-from iris.coords import DimCoord
+import pytest
 from iris.coord_systems import CoordSystem, GeogCS, TransverseMercator
+from iris.coords import DimCoord
+from iris.cube import Cube
 from iris.tests import IrisTest
 
 from improver.synthetic_data.set_up_test_cubes import set_up_variable_cube
 from improver.utilities.spatial import DistanceBetweenGridSquares
 
-
 EARTH_RADIUS = 6371229.0  # metres
 
 TEST_LATITUDES = np.array([0, 10, 20])