diff --git a/Pipfile b/Pipfile
index 9f9f1a49..701ad827 100644
--- a/Pipfile
+++ b/Pipfile
@@ -16,7 +16,7 @@ tensorboardX = "==2.0.*"
 requests = "~=2.22"
 transformers = "~=2.3"
 radam = {git = "https://github.com/LiyuanLucasLiu/RAdam"}
-sentencepiece = ">=0.1.83"
+sentencepiece = ">=0.1.83,<0.2.0"
 
 [requires]
 python_version = "3.7"
diff --git a/genienlp/data_utils/embeddings.py b/genienlp/data_utils/embeddings.py
index 1fda67b2..4c391efe 100644
--- a/genienlp/data_utils/embeddings.py
+++ b/genienlp/data_utils/embeddings.py
@@ -160,6 +160,7 @@ class PretrainedLMEmbedding(torch.nn.Module):
 def _is_bert(embedding_name):
     return embedding_name.startswith('bert-')
 
+
 def _is_xlmr(embedding_name):
     return embedding_name.startswith('xlm-roberta-')
 
diff --git a/genienlp/data_utils/numericalizer/masked_bert_tokenizer.py b/genienlp/data_utils/numericalizer/masked_tokenizer.py
similarity index 100%
rename from genienlp/data_utils/numericalizer/masked_bert_tokenizer.py
rename to genienlp/data_utils/numericalizer/masked_tokenizer.py
diff --git a/genienlp/data_utils/numericalizer/transformer.py b/genienlp/data_utils/numericalizer/transformer.py
index 3feb5cbc..b47b0406 100644
--- a/genienlp/data_utils/numericalizer/transformer.py
+++ b/genienlp/data_utils/numericalizer/transformer.py
@@ -31,7 +31,7 @@ import os
 import torch
 
 from .decoder_vocab import DecoderVocabulary
-from .masked_bert_tokenizer import MaskedBertTokenizer, MaskedXLMRobertaTokenizer
+from .masked_tokenizer import MaskedBertTokenizer, MaskedXLMRobertaTokenizer
 from .sequential_field import SequentialField
 from transformers.tokenization_xlnet import SPIECE_UNDERLINE
 
diff --git a/genienlp/tasks/base_dataset.py b/genienlp/tasks/base_dataset.py
index d5dabeb2..511812dc 100644
--- a/genienlp/tasks/base_dataset.py
+++ b/genienlp/tasks/base_dataset.py
@@ -1,7 +1,7 @@
 import os
 import zipfile
 import tarfile
-from six.moves import urllib
+import urllib
 import requests
 
 import torch.utils.data
diff --git a/setup.py b/setup.py
index d5b4404c..561985ab 100644
--- a/setup.py
+++ b/setup.py
@@ -55,6 +55,7 @@ setuptools.setup(
         'pyrouge>=0.1.3',
         'sacrebleu~=1.0',
         'requests~=2.22',
-        'transformers~=2.3'
+        'transformers~=2.3',
+        'sentencepiece>=0.1.83,<0.2.0'
     ]
 )