diff --git a/python/sglang/srt/openai_api/protocol.py b/python/sglang/srt/openai_api/protocol.py
index 3f15e229c..61b4df50a 100644
--- a/python/sglang/srt/openai_api/protocol.py
+++ b/python/sglang/srt/openai_api/protocol.py
@@ -236,7 +236,7 @@ ChatCompletionMessageContentPart = Union[
 
 
 class ChatCompletionMessageGenericParam(BaseModel):
-    role: Literal["system", "assistant"]
+    role: Literal["system", "assistant", "tool"]
     content: Union[str, List[ChatCompletionMessageContentTextPart]]