diff --git a/graphstorm-processing/graphstorm_processing/data_transformations/dist_label_loader.py b/graphstorm-processing/graphstorm_processing/data_transformations/dist_label_loader.py
index cd0ba563f..a85299947 100644
--- a/graphstorm-processing/graphstorm_processing/data_transformations/dist_label_loader.py
+++ b/graphstorm-processing/graphstorm_processing/data_transformations/dist_label_loader.py
@@ -75,9 +75,9 @@ class CustomSplit:
     ----------
     train : list[str]
         Paths of the training mask parquet files.
-    valid : str
+    valid : list[str]
         Paths of the validation mask parquet files.
-    test : str
+    test : list[str]
         Paths of the testing mask parquet files.
     mask_columns : list[str]
         List of columns that contain original string ids.