diff --git a/python/sglang/srt/disaggregation/mini_lb.py b/python/sglang/srt/disaggregation/mini_lb.py
index fdc9f2f45..55db8fa03 100644
--- a/python/sglang/srt/disaggregation/mini_lb.py
+++ b/python/sglang/srt/disaggregation/mini_lb.py
@@ -232,6 +232,9 @@ async def handle_generate_request(request_data: dict):
                     yield b"data: " + orjson.dumps(
                         error_msg, option=orjson.OPT_NON_STR_KEYS
                     ) + b"\n\n"
+                finally:
+                    if prefill_response is not None:
+                        await prefill_response.release()
 
         return StreamingResponse(
             stream_results(),