diff --git a/lagent/llms/openai.py b/lagent/llms/openai.py
index 83c13b3..b183483 100644
--- a/lagent/llms/openai.py
+++ b/lagent/llms/openai.py
@@ -4,7 +4,6 @@
 import random
 import time
 import traceback
-import uuid
 import warnings
 from concurrent.futures import ThreadPoolExecutor
 from logging import getLogger
@@ -16,8 +15,6 @@
 import requests
 from openai import NOT_GIVEN, APITimeoutError, AsyncOpenAI
 from openai.types.chat import ChatCompletion
-from openai.types.chat.chat_completion import Choice
-from openai.types.chat.chat_completion_message import ChatCompletionMessage
 
 from lagent.schema import ModelStatusCode
 from lagent.utils import filter_suffix
@@ -25,6 +22,8 @@
 
 warnings.simplefilter('default')
 
+logger = getLogger(__name__)
+
 OPENAI_API_BASE = 'https://api.openai.com/v1/chat/completions'
 
 
@@ -846,15 +845,15 @@ def __init__(
         self.extra_body = extra_body
 
     async def chat(self, messages: list[dict], session_id: str | int = None, **kwargs) -> ChatCompletion:
-        fallback_response = ChatCompletion(
-            id=f'chatcmpl-{uuid.uuid4()}',
-            object='chat.completion',
-            created=int(time.time()),
-            model=self.model,
-            choices=[
-                Choice(message=ChatCompletionMessage(role='assistant', content=''), finish_reason='stop', index=0)
-            ],
+        _RETRYABLE_STRINGS = (
+            "用户额度不足",
+            "剩余额度",
+            "TimeoutError",
+            "litellm.BadRequestError",
+            "litellm.APIError: APIError",
+            "Call `/v1/models` to view available models",
         )
+        last_exc: Exception | None = None
         for attempt in range(self.max_retry):
             try:
                 client = random.choice(self.clients)
@@ -872,25 +871,19 @@ async def chat(self, messages: list[dict], session_id: str | int = None, **kwarg
                 )
                 return response
             except (APITimeoutError, TimeoutError) as e:
-                print(f"LLM Call Timeout: {e}")
-                if attempt == self.max_retry - 1:
-                    return fallback_response
-                await asyncio.sleep(self.sleep_interval)
+                last_exc = e
+                logger.warning("LLM call timeout (attempt %d/%d): %s", attempt + 1, self.max_retry, e)
+                if attempt < self.max_retry - 1:
+                    await asyncio.sleep(self.sleep_interval)
             except Exception as e:
-                for val in [
-                    "用户额度不足",
-                    "剩余额度",
-                    "TimeoutError",
-                    "litellm.BadRequestError",
-                    "litellm.APIError: APIError",
-                    "Call `/v1/models` to view available models",
-                ]:
-                    if val in str(e):
-                        print(f"LLM Call Error: {e}")
-                        if attempt == self.max_retry - 1:
-                            return fallback_response
+                last_exc = e
+                err_str = str(e)
+                if any(val in err_str for val in _RETRYABLE_STRINGS):
+                    logger.warning("LLM call error (attempt %d/%d): %s", attempt + 1, self.max_retry, e)
+                    if attempt < self.max_retry - 1:
                         await asyncio.sleep(self.sleep_interval)
-                        break
                 else:
-                    return fallback_response
-        return fallback_response
+                    raise
+        raise RuntimeError(
+            f"LLM call failed after {self.max_retry} retries"
+        ) from last_exc