diff --git a/tokenization_chatglm.py b/tokenization_chatglm.py
index caa33d8..0583e9a 100644
--- a/tokenization_chatglm.py
+++ b/tokenization_chatglm.py
@@ -253,29 +253,20 @@ class ChatGLMTokenizer(PreTrainedTokenizer):
 
         return seq
 
-    def decode(
+    def _decode(
             self,
-            token_ids: Union[List[int], List[List[int]]],
+            token_ids: Union[int, List[int]],
             skip_special_tokens: bool = False,
             clean_up_tokenization_spaces: bool = True,
-            spaces_between_special_tokens: bool = True,
             **kwargs
     ) -> str:
-        if not isinstance(token_ids, list):
+        if isinstance(token_ids, int):
             token_ids = [token_ids]
         if len(token_ids) == 0:
             return ""
-        if isinstance(token_ids[0], list):
-            tokens = []
-            for single_token_ids in token_ids:
-                if self.pad_token_id in single_token_ids:  # remove pad
-                    single_token_ids = list(filter((self.pad_token_id).__ne__, single_token_ids))
-                tokens.append(self.sp_tokenizer.decode(single_token_ids))
-            return (tokens)
-        else:
-            if self.pad_token_id in token_ids:  # remove pad
-                token_ids = list(filter((self.pad_token_id).__ne__, token_ids))
-            return self.sp_tokenizer.decode(token_ids)
+        if self.pad_token_id in token_ids:  # remove pad
+            token_ids = list(filter((self.pad_token_id).__ne__, token_ids))
+        return self.sp_tokenizer.decode(token_ids)
 
     def _convert_token_to_id(self, token):
         """ Converts a token (str) in an id using the vocab. """