diff --git a/lmdeploy/serve/openai/protocol.py b/lmdeploy/serve/openai/protocol.py
index b4eeadff7..756af1a4c 100644
--- a/lmdeploy/serve/openai/protocol.py
+++ b/lmdeploy/serve/openai/protocol.py
@@ -28,7 +28,7 @@ class ModelPermission(BaseModel):
     allow_fine_tuning: bool = False
     organization: str = '*'
     group: Optional[str] = None
-    is_blocking: str = False
+    is_blocking: bool = False
 
 
 class ModelCard(BaseModel):