diff --git a/python/gtsam/tests/test_ShonanAveraging.py b/python/gtsam/tests/test_ShonanAveraging.py
index 29a14b1b6..19b9f8dc1 100644
--- a/python/gtsam/tests/test_ShonanAveraging.py
+++ b/python/gtsam/tests/test_ShonanAveraging.py
@@ -199,7 +199,7 @@ class TestShonanAveraging(GtsamTestCase):
         
         # map all angles to [0,360)
         thetas_deg = thetas_deg % 360
-        thetas_deg -= max(thetas_deg)
+        thetas_deg -= thetas_deg[0]
         
         expected_thetas_deg = np.array([0.0, 90.0, 0.0])
         np.testing.assert_allclose(thetas_deg, expected_thetas_deg, atol=0.1)