diff --git a/openmc/data/thermal.py b/openmc/data/thermal.py
index 067c0a7034..5f939e59e8 100644
--- a/openmc/data/thermal.py
+++ b/openmc/data/thermal.py
@@ -766,8 +766,8 @@ class ThermalScattering(EqualityMixin):
         """
         with tempfile.TemporaryDirectory() as tmpdir:
             # Run NJOY to create an ACE library
-            kwargs.setdefault('ace', os.path.join(tmpdir, 'ace'))
-            kwargs.setdefault('xsdir', os.path.join(tmpdir, 'xsdir'))
+            kwargs.setdefault('output_dir', tmpdir)
+            kwargs.setdefault('ace', os.path.join(kwargs['output_dir'], 'ace'))
             kwargs['evaluation'] = evaluation
             kwargs['evaluation_thermal'] = evaluation_thermal
             make_ace_thermal(filename, filename_thermal, temperatures, **kwargs)