diff --git a/sdk/formrecognizer/azure-ai-formrecognizer/azure/ai/formrecognizer/aio/_form_recognizer_client_async.py b/sdk/formrecognizer/azure-ai-formrecognizer/azure/ai/formrecognizer/aio/_form_recognizer_client_async.py
index 3430e4f86cb7..3ede9c9ae0a3 100644
--- a/sdk/formrecognizer/azure-ai-formrecognizer/azure/ai/formrecognizer/aio/_form_recognizer_client_async.py
+++ b/sdk/formrecognizer/azure-ai-formrecognizer/azure/ai/formrecognizer/aio/_form_recognizer_client_async.py
@@ -344,7 +344,7 @@ async def begin_recognize_business_cards_from_url(
 
     @distributed_trace_async
     async def begin_recognize_id_documents(
-        self, id_document, **kwargs: Any
+        self, id_document: Union[bytes, IO[bytes]], **kwargs: Any
     ) -> AsyncLROPoller[List[RecognizedForm]]:
         """Extract field text and semantic values from a given ID document.
         The input document must be of one of the supported content types - 'application/pdf',