diff --git a/src/google/adk/flows/llm_flows/base_llm_flow.py b/src/google/adk/flows/llm_flows/base_llm_flow.py
index 3a108b4..e9daa1e 100644
--- a/src/google/adk/flows/llm_flows/base_llm_flow.py
+++ b/src/google/adk/flows/llm_flows/base_llm_flow.py
@@ -261,7 +261,6 @@ class BaseLlmFlow(ABC):
 
     # Calls the LLM.
     model_response_event = Event(
-        id=Event.new_id(),
         invocation_id=invocation_context.invocation_id,
         author=invocation_context.agent.name,
         branch=invocation_context.branch,
@@ -273,6 +272,8 @@ class BaseLlmFlow(ABC):
       async for event in self._postprocess_async(
           invocation_context, llm_request, llm_response, model_response_event
       ):
+        # Use a new id for every event.
+        event.id = Event.new_id()
         yield event
 
   async def _preprocess_async(