diff --git a/library/config_util.py b/library/config_util.py
index 8f01e1f6..6f243aac 100644
--- a/library/config_util.py
+++ b/library/config_util.py
@@ -512,8 +512,7 @@ def generate_dataset_group_by_blueprint(dataset_group_blueprint: DatasetGroupBlu
             subset_blueprint.params.token_warmup_step = 0
 
             if subset_klass != DreamBoothSubset or (subset_klass == DreamBoothSubset and not subset_blueprint.params.is_reg):
-                subset = subset_klass(**asdict(subset_blueprint.params))
-                subsets.append(subset)
+                subsets.append(subset_klass(**asdict(subset_blueprint.params)))
 
         dataset = dataset_klass(subsets=subsets, is_train=False, **asdict(dataset_blueprint.params))
         val_datasets.append(dataset)