diff --git a/textsplitter/chinese_text_splitter.py b/textsplitter/chinese_text_splitter.py
index e7694df..b6e7940 100644
--- a/textsplitter/chinese_text_splitter.py
+++ b/textsplitter/chinese_text_splitter.py
@@ -5,7 +5,7 @@ from configs.model_config import SENTENCE_SIZE
 
 
 class ChineseTextSplitter(CharacterTextSplitter):
-    def __init__(self, pdf: bool = False, sentence_size: int = None, **kwargs):
+    def __init__(self, pdf: bool = False, sentence_size: int = SENTENCE_SIZE, **kwargs):
         super().__init__(**kwargs)
         self.pdf = pdf
         self.sentence_size = sentence_size