diff --git a/proteinflow/__init__.py b/proteinflow/__init__.py
index 94ae7bb..4509910 100644
--- a/proteinflow/__init__.py
+++ b/proteinflow/__init__.py
@@ -530,7 +530,7 @@ def split_data(
         warnings.warn(
             "Found an existing dictionary for excluded chains. proteinflow will load it and ignore the exclusion parameters! Run with --ignore_existing to overwrite the splitting."
         )
-        excluded_biounits = []
+        excluded_biounits = None
     else:
         if exclude_chains_file is not None or exclude_chains is not None:
             excluded_biounits = _get_excluded_files(
diff --git a/proteinflow/split/__init__.py b/proteinflow/split/__init__.py
index 5be1515..28a5fec 100644
--- a/proteinflow/split/__init__.py
+++ b/proteinflow/split/__init__.py
@@ -1400,7 +1400,14 @@ def _split_data(
 
     """
     if excluded_biounits is None:
-        excluded_biounits = []
+        if os.path.exists(os.path.join(dataset_path, "splits_dict", "excluded.pickle")):
+            with open(
+                os.path.join(dataset_path, "splits_dict", "excluded.pickle"), "rb"
+            ) as f:
+                excluded_clusters_dict = pickle.load(f)
+            excluded_biounits = _biounits_in_clusters_dict(excluded_clusters_dict, [])
+        else:
+            excluded_biounits = []
 
     dict_folder = os.path.join(dataset_path, "splits_dict")
     with open(os.path.join(dict_folder, "train.pickle"), "rb") as f:
@@ -1428,42 +1435,48 @@ def _split_data(
         os.makedirs(test_path)
 
     if len(excluded_biounits) > 0:
-        set_to_exclude = set(excluded_biounits)
-        excluded_biounits = set()
-        excluded_clusters_dict = defaultdict(list)
-        for clusters_dict in [
-            train_clusters_dict,
-            valid_clusters_dict,
-            test_clusters_dict,
-        ]:
-            for cluster in list(clusters_dict.keys()):
-                idx_to_exclude = []
-                exclude_whole_cluster = False
-                for i, chain in enumerate(clusters_dict[cluster]):
-                    if chain[0] in set_to_exclude:
-                        if exclude_clusters:
-                            if exclude_based_on_cdr is not None and cluster.endswith(
-                                exclude_based_on_cdr
-                            ):
-                                exclude_whole_cluster = True
-                            elif exclude_based_on_cdr is None:
-                                exclude_whole_cluster = True
-                        if exclude_whole_cluster:
-                            break
-                        excluded_clusters_dict[cluster].append(chain)
-                        idx_to_exclude.append(i)
-                if exclude_whole_cluster:
-                    excluded_clusters_dict[cluster] = clusters_dict.pop(cluster)
-                else:
-                    clusters_dict[cluster] = [
-                        x
-                        for i, x in enumerate(clusters_dict[cluster])
-                        if i not in idx_to_exclude
-                    ]
-                    if len(clusters_dict[cluster]) == 0:
-                        clusters_dict.pop(cluster)
-        excluded_biounits.update(set_to_exclude)
-        excluded_clusters_dict = {k: list(v) for k, v in excluded_clusters_dict.items()}
+        if not os.path.exists(
+            os.path.join(dataset_path, "splits_dict", "excluded.pickle")
+        ):
+            set_to_exclude = set(excluded_biounits)
+            excluded_biounits = set()
+            excluded_clusters_dict = defaultdict(list)
+            for clusters_dict in [
+                train_clusters_dict,
+                valid_clusters_dict,
+                test_clusters_dict,
+            ]:
+                for cluster in list(clusters_dict.keys()):
+                    idx_to_exclude = []
+                    exclude_whole_cluster = False
+                    for i, chain in enumerate(clusters_dict[cluster]):
+                        if chain[0] in set_to_exclude:
+                            if exclude_clusters:
+                                if (
+                                    exclude_based_on_cdr is not None
+                                    and cluster.endswith(exclude_based_on_cdr)
+                                ):
+                                    exclude_whole_cluster = True
+                                elif exclude_based_on_cdr is None:
+                                    exclude_whole_cluster = True
+                            if exclude_whole_cluster:
+                                break
+                            excluded_clusters_dict[cluster].append(chain)
+                            idx_to_exclude.append(i)
+                    if exclude_whole_cluster:
+                        excluded_clusters_dict[cluster] = clusters_dict.pop(cluster)
+                    else:
+                        clusters_dict[cluster] = [
+                            x
+                            for i, x in enumerate(clusters_dict[cluster])
+                            if i not in idx_to_exclude
+                        ]
+                        if len(clusters_dict[cluster]) == 0:
+                            clusters_dict.pop(cluster)
+            excluded_clusters_dict = {
+                k: list(v) for k, v in excluded_clusters_dict.items()
+            }
+            excluded_biounits = _biounits_in_clusters_dict(excluded_clusters_dict, [])
         excluded_path = os.path.join(dataset_path, "excluded")
         if not os.path.exists(excluded_path):
             os.makedirs(excluded_path)
@@ -1479,16 +1492,6 @@ def _split_data(
         print("Moving excluded files...")
         for biounit in tqdm(excluded_biounits):
             shutil.move(os.path.join(dataset_path, biounit), excluded_path)
-    elif os.path.exists(os.path.join(dict_folder, "excluded.pickle")):
-        with open(os.path.join(dict_folder, "excluded.pickle"), "rb") as f:
-            excluded_clusters_dict = pickle.load(f)
-        excluded_biounits = _biounits_in_clusters_dict(excluded_clusters_dict, [])
-        excluded_path = os.path.join(dataset_path, "excluded")
-        if not os.path.exists(excluded_path):
-            os.makedirs(excluded_path)
-        print("Moving excluded files...")
-        for biounit in tqdm(excluded_biounits):
-            shutil.move(os.path.join(dataset_path, biounit), excluded_path)
     print("Moving files in the train set...")
     for biounit in tqdm(train_biounits):
         shutil.move(os.path.join(dataset_path, biounit), train_path)