diff --git a/src/llmtuner/tuner/core/loader.py b/src/llmtuner/tuner/core/loader.py
index d4ce6e50..646a0509 100644
--- a/src/llmtuner/tuner/core/loader.py
+++ b/src/llmtuner/tuner/core/loader.py
@@ -128,7 +128,7 @@ def load_model_and_tokenizer(
     model = init_adapter(model, model_args, finetuning_args, is_trainable, is_mergeable)
 
     if stage == "rm" or stage == "ppo": # add value head
-        model = AutoModelForCausalLMWithValueHead.from_pretrained(model)
+        model: "AutoModelForCausalLMWithValueHead" = AutoModelForCausalLMWithValueHead.from_pretrained(model)
         reset_logging()
 
         if stage == "rm" and model_args.checkpoint_dir is not None: # load valuehead weights to evaluate reward model
diff --git a/src/llmtuner/webui/chat.py b/src/llmtuner/webui/chat.py
index 773fb7c7..01e6f0e4 100644
--- a/src/llmtuner/webui/chat.py
+++ b/src/llmtuner/webui/chat.py
@@ -10,7 +10,7 @@ from llmtuner.webui.locales import ALERTS
 
 class WebChatModel(ChatModel):
 
-    def __init__(self, args: Optional[Dict[str, Any]]) -> None:
+    def __init__(self, args: Optional[Dict[str, Any]] = None) -> None:
         self.model = None
         self.tokenizer = None
         self.generating_args = GeneratingArguments()
diff --git a/src/train_bash.py b/src/train_bash.py
index 0facef9a..9ddd0586 100644
--- a/src/train_bash.py
+++ b/src/train_bash.py
@@ -1,5 +1,6 @@
 from llmtuner import run_exp
 
+
 def main():
     run_exp()