diff --git a/fastchat/protocol/openai_api_protocol.py b/fastchat/protocol/openai_api_protocol.py
index bb50a5ef0..990f1f804 100644
--- a/fastchat/protocol/openai_api_protocol.py
+++ b/fastchat/protocol/openai_api_protocol.py
@@ -24,7 +24,7 @@ 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):