diff --git a/src/NERDA/preprocessing.py b/src/NERDA/preprocessing.py
index 4dd7dae..4d481ae 100644
--- a/src/NERDA/preprocessing.py
+++ b/src/NERDA/preprocessing.py
@@ -99,6 +99,10 @@ def __getitem__(self, item):
         # compute padding length
         if self.pad_sequences:
             padding_len = self.max_len - len(input_ids)
+             if self.pad_token_id == None:
+                input_ids = input_ids + ([0] * padding_len)
+            else:
+                input_ids = input_ids + ([self.pad_token_id] * padding_len)
             input_ids = input_ids + ([self.pad_token_id] * padding_len)
             masks = masks + ([0] * padding_len)  
             offsets = offsets + ([0] * padding_len)