diff --git a/src/transformers/tokenization_xlnet.py b/src/transformers/tokenization_xlnet.py
index 51e167d2c7f..e3ebc710724 100644
--- a/src/transformers/tokenization_xlnet.py
+++ b/src/transformers/tokenization_xlnet.py
@@ -236,7 +236,6 @@ class XLNetTokenizer(PreTrainedTokenizer):
         if token_ids_1 is None, only returns the first portion of the mask (0's).
         """
         sep = [self.sep_token_id]
-        cls = [self.cls_token_id]
         cls_segment_id = [2]
 
         if token_ids_1 is None: