diff --git a/graphium/data/datamodule.py b/graphium/data/datamodule.py
index 8b043fa1d..b85fd664c 100644
--- a/graphium/data/datamodule.py
+++ b/graphium/data/datamodule.py
@@ -1975,7 +1975,7 @@ def get_data_hash(self):
         # pop epoch_sampling_fraction out when creating hash
         # so that the data cache does not need to be regenerated
         # when epoch_sampling_fraction has changed.
-        for task_key, task_args in self.task_specific_args.items():
+        for task_key, task_args in deepcopy(self.task_specific_args).items():
             if isinstance(task_args, DatasetProcessingParams):
                 task_args = task_args.__dict__  # Convert the class to a dictionary