diff --git a/autogen/agentchat/groupchat.py b/autogen/agentchat/groupchat.py
index 8c4809343495..bd5774cb1a62 100644
--- a/autogen/agentchat/groupchat.py
+++ b/autogen/agentchat/groupchat.py
@@ -103,9 +103,9 @@ def custom_speaker_selection_func(
     messages: List[Dict]
     llm_config: Optional[Union[Dict, Literal[False]]] = None
     model_client_cls: Optional[Union[ModelClient, List[ModelClient]]] = None
-    max_round: Optional[int] = 10
-    admin_name: Optional[str] = "Admin"
-    func_call_filter: Optional[bool] = True
+    max_round: int = 10
+    admin_name: str = "Admin"
+    func_call_filter: bool = True
     speaker_selection_method: Union[Literal["auto", "manual", "random", "round_robin"], Callable] = "auto"
     max_retries_for_selecting_speaker: int = 2
     allow_repeat_speaker: Optional[Union[bool, List[Agent]]] = None