diff --git a/tests/command_line/test_average.py b/tests/command_line/test_average.py
index d176d21c0..c18c8985c 100644
--- a/tests/command_line/test_average.py
+++ b/tests/command_line/test_average.py
@@ -9,7 +9,7 @@
 
 
 @pytest.mark.parametrize("use_mpi", [True, False])
-def test_average(dials_data, tmpdir, use_mpi):
+def test_average(dials_data, tmp_path, use_mpi):
     # Only allow MPI tests if we've got MPI capabilities
     if use_mpi:
         pytest.importorskip("mpi4py")