diff --git a/python/packages/autogen-core/src/autogen_core/_routed_agent.py b/python/packages/autogen-core/src/autogen_core/_routed_agent.py
index a5908278cab9..bd8f3194fa8e 100644
--- a/python/packages/autogen-core/src/autogen_core/_routed_agent.py
+++ b/python/packages/autogen-core/src/autogen_core/_routed_agent.py
@@ -164,7 +164,7 @@ async def wrapper(self: AgentT, message: ReceivesT, ctx: MessageContext) -> Prod
 
         return wrapper_handler
 
-    if func is None and not callable(func):
+    if func is None and not callable(func) or getattr(func, "__isabstractmethod__", False):
         return decorator
     elif callable(func):
         return decorator(func)
@@ -284,7 +284,7 @@ async def wrapper(self: AgentT, message: ReceivesT, ctx: MessageContext) -> None
 
         return wrapper_handler
 
-    if func is None and not callable(func):
+    if func is None and not callable(func) or getattr(func, "__isabstractmethod__", False):
         return decorator
     elif callable(func):
         return decorator(func)
@@ -404,7 +404,7 @@ async def wrapper(self: AgentT, message: ReceivesT, ctx: MessageContext) -> Prod
 
         return wrapper_handler
 
-    if func is None and not callable(func):
+    if func is None and not callable(func) or getattr(func, "__isabstractmethod__", False):
         return decorator
     elif callable(func):
         return decorator(func)