diff --git a/llama_stack/providers/inline/agents/meta_reference/responses/openai_responses.py b/llama_stack/providers/inline/agents/meta_reference/responses/openai_responses.py
index fc7cf2989..c4030b182 100644
--- a/llama_stack/providers/inline/agents/meta_reference/responses/openai_responses.py
+++ b/llama_stack/providers/inline/agents/meta_reference/responses/openai_responses.py
@@ -240,6 +240,7 @@ class OpenAIResponsesImpl:
                 raise InvalidConversationIdError(conversation)
 
             # Check conversation exists (raises ConversationNotFoundError if not)
+            _ = await self.conversations_api.get_conversation(conversation)
             input = await self._load_conversation_context(conversation, input)
 
         stream_gen = self._create_streaming_response(