diff --git a/pandas/tests/series/test_arithmetic.py b/pandas/tests/series/test_arithmetic.py
index 75237be212030..b40e2e99dae2e 100644
--- a/pandas/tests/series/test_arithmetic.py
+++ b/pandas/tests/series/test_arithmetic.py
@@ -754,6 +754,9 @@ def test_series_add_tz_mismatch_converts_to_utc(self):
         uts2 = ser2.tz_convert("utc")
         expected = uts1 + uts2
 
+        # sort since input indexes are not equal
+        expected = expected.sort_index()
+
         assert result.index.tz is timezone.utc
         tm.assert_series_equal(result, expected)