diff --git a/bipia/model/llm_worker.py b/bipia/model/llm_worker.py
index 684105a..ae23b94 100644
--- a/bipia/model/llm_worker.py
+++ b/bipia/model/llm_worker.py
@@ -208,7 +208,7 @@ def load_model(self):
         return self.model
 
     def load_tokenizer(self):
-        revision = "main"
+        revision = "50f5173d932e8e61f858120bcb800b97af589f46"
         self.tokenizer = AutoTokenizer.from_pretrained(
             "EleutherAI/pythia-160m", revision=revision
         )