diff --git a/src/cnlpt/cnlp_processors.py b/src/cnlpt/cnlp_processors.py
index f446898e..1918b46e 100644
--- a/src/cnlpt/cnlp_processors.py
+++ b/src/cnlpt/cnlp_processors.py
@@ -185,8 +185,11 @@ def __init__(self, data_dir: str, tasks: Set[str] = None, max_train_items=-1):
             dataset_tasks = first_split.features.keys() - set(
                 ["text", "text_a", "text_b"]
             )
-            active_tasks = set(tasks).intersection(dataset_tasks)
-            active_tasks = list(active_tasks)
+            if tasks is None:
+                active_tasks = list(dataset_tasks)
+            else:
+                active_tasks = set(tasks).intersection(dataset_tasks)
+                active_tasks = list(active_tasks)
             active_tasks.sort()
             self.dataset.task_output_modes = {}
         elif ext_check_file.endswith("json"):