diff --git a/src/transformers/tokenization_utils.py b/src/transformers/tokenization_utils.py
index <HASH>..<HASH> 100644
--- a/src/transformers/tokenization_utils.py
+++ b/src/transformers/tokenization_utils.py
@@ -1126,8 +1126,7 @@ class PreTrainedTokenizer(object):
 
         input_ids = []
         for ids_or_pair_ids in batch_text_or_text_pairs:
-            if isinstance(ids_or_pair_ids, (list, tuple)):
-                assert len(ids_or_pair_ids) == 2
+            if isinstance(ids_or_pair_ids, (list, tuple)) and len(ids_or_pair_ids) == 2:
                 ids, pair_ids = ids_or_pair_ids
             else:
                 ids, pair_ids = ids_or_pair_ids, None
Fix batch_encode_plus (#<I>)