diff --git a/unfair/model/models.py b/unfair/model/models.py
index a998570..46c6e95 100644
--- a/unfair/model/models.py
+++ b/unfair/model/models.py
@@ -840,7 +840,7 @@ def test(
         dat_in,
         dat_out_classes,
         dat_extra,
-        graph_prms=copy.copy({"sort_by_unfairness": True, "dur_s": None}),
+        graph_prms=copy.deepcopy({"sort_by_unfairness": True, "dur_s": None}),
     ):
         """
         Tests this model on the provided dataset and returns the test accuracy
diff --git a/unfair/model/train.py b/unfair/model/train.py
index 6487f9d..50a5cf7 100755
--- a/unfair/model/train.py
+++ b/unfair/model/train.py
@@ -443,7 +443,7 @@ def prepare_args(args_):
     # any manually-specified values. This allows the caller to specify values
     # only for parameters that they care about while ensuring that all
     # parameters have values.
-    args = copy.copy(defaults.DEFAULTS)
+    args = copy.deepcopy(defaults.DEFAULTS)
     args.update(args_)
     return args